xref: /openbmc/linux/drivers/tty/vt/vt.c (revision ba61bb17)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  *  Copyright (C) 1991, 1992  Linus Torvalds
4  */
5 
6 /*
7  * Hopefully this will be a rather complete VT102 implementation.
8  *
9  * Beeping thanks to John T Kohl.
10  *
11  * Virtual Consoles, Screen Blanking, Screen Dumping, Color, Graphics
12  *   Chars, and VT100 enhancements by Peter MacDonald.
13  *
14  * Copy and paste function by Andrew Haylett,
15  *   some enhancements by Alessandro Rubini.
16  *
17  * Code to check for different video-cards mostly by Galen Hunt,
18  * <g-hunt@ee.utah.edu>
19  *
20  * Rudimentary ISO 10646/Unicode/UTF-8 character set support by
21  * Markus Kuhn, <mskuhn@immd4.informatik.uni-erlangen.de>.
22  *
23  * Dynamic allocation of consoles, aeb@cwi.nl, May 1994
24  * Resizing of consoles, aeb, 940926
25  *
26  * Code for xterm like mouse click reporting by Peter Orbaek 20-Jul-94
27  * <poe@daimi.aau.dk>
28  *
29  * User-defined bell sound, new setterm control sequences and printk
30  * redirection by Martin Mares <mj@k332.feld.cvut.cz> 19-Nov-95
31  *
32  * APM screenblank bug fixed Takashi Manabe <manabe@roy.dsl.tutics.tut.jp>
33  *
34  * Merge with the abstract console driver by Geert Uytterhoeven
35  * <geert@linux-m68k.org>, Jan 1997.
36  *
37  *   Original m68k console driver modifications by
38  *
39  *     - Arno Griffioen <arno@usn.nl>
40  *     - David Carter <carter@cs.bris.ac.uk>
41  *
42  *   The abstract console driver provides a generic interface for a text
43  *   console. It supports VGA text mode, frame buffer based graphical consoles
44  *   and special graphics processors that are only accessible through some
45  *   registers (e.g. a TMS340x0 GSP).
46  *
47  *   The interface to the hardware is specified using a special structure
48  *   (struct consw) which contains function pointers to console operations
49  *   (see <linux/console.h> for more information).
50  *
51  * Support for changeable cursor shape
52  * by Pavel Machek <pavel@atrey.karlin.mff.cuni.cz>, August 1997
53  *
54  * Ported to i386 and con_scrolldelta fixed
55  * by Emmanuel Marty <core@ggi-project.org>, April 1998
56  *
57  * Resurrected character buffers in videoram plus lots of other trickery
58  * by Martin Mares <mj@atrey.karlin.mff.cuni.cz>, July 1998
59  *
60  * Removed old-style timers, introduced console_timer, made timer
61  * deletion SMP-safe.  17Jun00, Andrew Morton
62  *
63  * Removed console_lock, enabled interrupts across all console operations
64  * 13 March 2001, Andrew Morton
65  *
66  * Fixed UTF-8 mode so alternate charset modes always work according
67  * to control sequences interpreted in do_con_trol function
68  * preserving backward VT100 semigraphics compatibility,
69  * malformed UTF sequences represented as sequences of replacement glyphs,
70  * original codes or '?' as a last resort if replacement glyph is undefined
71  * by Adam Tla/lka <atlka@pg.gda.pl>, Aug 2006
72  */
73 
74 #include <linux/module.h>
75 #include <linux/types.h>
76 #include <linux/sched/signal.h>
77 #include <linux/tty.h>
78 #include <linux/tty_flip.h>
79 #include <linux/kernel.h>
80 #include <linux/string.h>
81 #include <linux/errno.h>
82 #include <linux/kd.h>
83 #include <linux/slab.h>
84 #include <linux/major.h>
85 #include <linux/mm.h>
86 #include <linux/console.h>
87 #include <linux/init.h>
88 #include <linux/mutex.h>
89 #include <linux/vt_kern.h>
90 #include <linux/selection.h>
91 #include <linux/tiocl.h>
92 #include <linux/kbd_kern.h>
93 #include <linux/consolemap.h>
94 #include <linux/timer.h>
95 #include <linux/interrupt.h>
96 #include <linux/workqueue.h>
97 #include <linux/pm.h>
98 #include <linux/font.h>
99 #include <linux/bitops.h>
100 #include <linux/notifier.h>
101 #include <linux/device.h>
102 #include <linux/io.h>
103 #include <linux/uaccess.h>
104 #include <linux/kdb.h>
105 #include <linux/ctype.h>
106 #include <linux/bsearch.h>
107 
108 #define MAX_NR_CON_DRIVER 16
109 
110 #define CON_DRIVER_FLAG_MODULE 1
111 #define CON_DRIVER_FLAG_INIT   2
112 #define CON_DRIVER_FLAG_ATTR   4
113 #define CON_DRIVER_FLAG_ZOMBIE 8
114 
115 struct con_driver {
116 	const struct consw *con;
117 	const char *desc;
118 	struct device *dev;
119 	int node;
120 	int first;
121 	int last;
122 	int flag;
123 };
124 
125 static struct con_driver registered_con_driver[MAX_NR_CON_DRIVER];
126 const struct consw *conswitchp;
127 
128 /* A bitmap for codes <32. A bit of 1 indicates that the code
129  * corresponding to that bit number invokes some special action
130  * (such as cursor movement) and should not be displayed as a
131  * glyph unless the disp_ctrl mode is explicitly enabled.
132  */
133 #define CTRL_ACTION 0x0d00ff81
134 #define CTRL_ALWAYS 0x0800f501	/* Cannot be overridden by disp_ctrl */
135 
136 /*
137  * Here is the default bell parameters: 750HZ, 1/8th of a second
138  */
139 #define DEFAULT_BELL_PITCH	750
140 #define DEFAULT_BELL_DURATION	(HZ/8)
141 #define DEFAULT_CURSOR_BLINK_MS	200
142 
143 struct vc vc_cons [MAX_NR_CONSOLES];
144 
145 #ifndef VT_SINGLE_DRIVER
146 static const struct consw *con_driver_map[MAX_NR_CONSOLES];
147 #endif
148 
149 static int con_open(struct tty_struct *, struct file *);
150 static void vc_init(struct vc_data *vc, unsigned int rows,
151 		    unsigned int cols, int do_clear);
152 static void gotoxy(struct vc_data *vc, int new_x, int new_y);
153 static void save_cur(struct vc_data *vc);
154 static void reset_terminal(struct vc_data *vc, int do_clear);
155 static void con_flush_chars(struct tty_struct *tty);
156 static int set_vesa_blanking(char __user *p);
157 static void set_cursor(struct vc_data *vc);
158 static void hide_cursor(struct vc_data *vc);
159 static void console_callback(struct work_struct *ignored);
160 static void con_driver_unregister_callback(struct work_struct *ignored);
161 static void blank_screen_t(struct timer_list *unused);
162 static void set_palette(struct vc_data *vc);
163 
164 #define vt_get_kmsg_redirect() vt_kmsg_redirect(-1)
165 
166 static int printable;		/* Is console ready for printing? */
167 int default_utf8 = true;
168 module_param(default_utf8, int, S_IRUGO | S_IWUSR);
169 int global_cursor_default = -1;
170 module_param(global_cursor_default, int, S_IRUGO | S_IWUSR);
171 
172 static int cur_default = CUR_DEFAULT;
173 module_param(cur_default, int, S_IRUGO | S_IWUSR);
174 
175 /*
176  * ignore_poke: don't unblank the screen when things are typed.  This is
177  * mainly for the privacy of braille terminal users.
178  */
179 static int ignore_poke;
180 
181 int do_poke_blanked_console;
182 int console_blanked;
183 
184 static int vesa_blank_mode; /* 0:none 1:suspendV 2:suspendH 3:powerdown */
185 static int vesa_off_interval;
186 static int blankinterval;
187 core_param(consoleblank, blankinterval, int, 0444);
188 
189 static DECLARE_WORK(console_work, console_callback);
190 static DECLARE_WORK(con_driver_unregister_work, con_driver_unregister_callback);
191 
192 /*
193  * fg_console is the current virtual console,
194  * last_console is the last used one,
195  * want_console is the console we want to switch to,
196  * saved_* variants are for save/restore around kernel debugger enter/leave
197  */
198 int fg_console;
199 int last_console;
200 int want_console = -1;
201 static int saved_fg_console;
202 static int saved_last_console;
203 static int saved_want_console;
204 static int saved_vc_mode;
205 static int saved_console_blanked;
206 
207 /*
208  * For each existing display, we have a pointer to console currently visible
209  * on that display, allowing consoles other than fg_console to be refreshed
210  * appropriately. Unless the low-level driver supplies its own display_fg
211  * variable, we use this one for the "master display".
212  */
213 static struct vc_data *master_display_fg;
214 
215 /*
216  * Unfortunately, we need to delay tty echo when we're currently writing to the
217  * console since the code is (and always was) not re-entrant, so we schedule
218  * all flip requests to process context with schedule-task() and run it from
219  * console_callback().
220  */
221 
222 /*
223  * For the same reason, we defer scrollback to the console callback.
224  */
225 static int scrollback_delta;
226 
227 /*
228  * Hook so that the power management routines can (un)blank
229  * the console on our behalf.
230  */
231 int (*console_blank_hook)(int);
232 
233 static DEFINE_TIMER(console_timer, blank_screen_t);
234 static int blank_state;
235 static int blank_timer_expired;
236 enum {
237 	blank_off = 0,
238 	blank_normal_wait,
239 	blank_vesa_wait,
240 };
241 
242 /*
243  * /sys/class/tty/tty0/
244  *
245  * the attribute 'active' contains the name of the current vc
246  * console and it supports poll() to detect vc switches
247  */
248 static struct device *tty0dev;
249 
250 /*
251  * Notifier list for console events.
252  */
253 static ATOMIC_NOTIFIER_HEAD(vt_notifier_list);
254 
255 int register_vt_notifier(struct notifier_block *nb)
256 {
257 	return atomic_notifier_chain_register(&vt_notifier_list, nb);
258 }
259 EXPORT_SYMBOL_GPL(register_vt_notifier);
260 
261 int unregister_vt_notifier(struct notifier_block *nb)
262 {
263 	return atomic_notifier_chain_unregister(&vt_notifier_list, nb);
264 }
265 EXPORT_SYMBOL_GPL(unregister_vt_notifier);
266 
267 static void notify_write(struct vc_data *vc, unsigned int unicode)
268 {
269 	struct vt_notifier_param param = { .vc = vc, .c = unicode };
270 	atomic_notifier_call_chain(&vt_notifier_list, VT_WRITE, &param);
271 }
272 
273 static void notify_update(struct vc_data *vc)
274 {
275 	struct vt_notifier_param param = { .vc = vc };
276 	atomic_notifier_call_chain(&vt_notifier_list, VT_UPDATE, &param);
277 }
278 /*
279  *	Low-Level Functions
280  */
281 
282 static inline bool con_is_fg(const struct vc_data *vc)
283 {
284 	return vc->vc_num == fg_console;
285 }
286 
287 static inline bool con_should_update(const struct vc_data *vc)
288 {
289 	return con_is_visible(vc) && !console_blanked;
290 }
291 
292 static inline unsigned short *screenpos(struct vc_data *vc, int offset, int viewed)
293 {
294 	unsigned short *p;
295 
296 	if (!viewed)
297 		p = (unsigned short *)(vc->vc_origin + offset);
298 	else if (!vc->vc_sw->con_screen_pos)
299 		p = (unsigned short *)(vc->vc_visible_origin + offset);
300 	else
301 		p = vc->vc_sw->con_screen_pos(vc, offset);
302 	return p;
303 }
304 
305 /* Called  from the keyboard irq path.. */
306 static inline void scrolldelta(int lines)
307 {
308 	/* FIXME */
309 	/* scrolldelta needs some kind of consistency lock, but the BKL was
310 	   and still is not protecting versus the scheduled back end */
311 	scrollback_delta += lines;
312 	schedule_console_callback();
313 }
314 
315 void schedule_console_callback(void)
316 {
317 	schedule_work(&console_work);
318 }
319 
320 static void con_scroll(struct vc_data *vc, unsigned int t, unsigned int b,
321 		enum con_scroll dir, unsigned int nr)
322 {
323 	u16 *clear, *d, *s;
324 
325 	if (t + nr >= b)
326 		nr = b - t - 1;
327 	if (b > vc->vc_rows || t >= b || nr < 1)
328 		return;
329 	if (con_is_visible(vc) && vc->vc_sw->con_scroll(vc, t, b, dir, nr))
330 		return;
331 
332 	s = clear = (u16 *)(vc->vc_origin + vc->vc_size_row * t);
333 	d = (u16 *)(vc->vc_origin + vc->vc_size_row * (t + nr));
334 
335 	if (dir == SM_UP) {
336 		clear = s + (b - t - nr) * vc->vc_cols;
337 		swap(s, d);
338 	}
339 	scr_memmovew(d, s, (b - t - nr) * vc->vc_size_row);
340 	scr_memsetw(clear, vc->vc_video_erase_char, vc->vc_size_row * nr);
341 }
342 
343 static void do_update_region(struct vc_data *vc, unsigned long start, int count)
344 {
345 	unsigned int xx, yy, offset;
346 	u16 *p;
347 
348 	p = (u16 *) start;
349 	if (!vc->vc_sw->con_getxy) {
350 		offset = (start - vc->vc_origin) / 2;
351 		xx = offset % vc->vc_cols;
352 		yy = offset / vc->vc_cols;
353 	} else {
354 		int nxx, nyy;
355 		start = vc->vc_sw->con_getxy(vc, start, &nxx, &nyy);
356 		xx = nxx; yy = nyy;
357 	}
358 	for(;;) {
359 		u16 attrib = scr_readw(p) & 0xff00;
360 		int startx = xx;
361 		u16 *q = p;
362 		while (xx < vc->vc_cols && count) {
363 			if (attrib != (scr_readw(p) & 0xff00)) {
364 				if (p > q)
365 					vc->vc_sw->con_putcs(vc, q, p-q, yy, startx);
366 				startx = xx;
367 				q = p;
368 				attrib = scr_readw(p) & 0xff00;
369 			}
370 			p++;
371 			xx++;
372 			count--;
373 		}
374 		if (p > q)
375 			vc->vc_sw->con_putcs(vc, q, p-q, yy, startx);
376 		if (!count)
377 			break;
378 		xx = 0;
379 		yy++;
380 		if (vc->vc_sw->con_getxy) {
381 			p = (u16 *)start;
382 			start = vc->vc_sw->con_getxy(vc, start, NULL, NULL);
383 		}
384 	}
385 }
386 
387 void update_region(struct vc_data *vc, unsigned long start, int count)
388 {
389 	WARN_CONSOLE_UNLOCKED();
390 
391 	if (con_should_update(vc)) {
392 		hide_cursor(vc);
393 		do_update_region(vc, start, count);
394 		set_cursor(vc);
395 	}
396 }
397 
398 /* Structure of attributes is hardware-dependent */
399 
400 static u8 build_attr(struct vc_data *vc, u8 _color, u8 _intensity, u8 _blink,
401     u8 _underline, u8 _reverse, u8 _italic)
402 {
403 	if (vc->vc_sw->con_build_attr)
404 		return vc->vc_sw->con_build_attr(vc, _color, _intensity,
405 		       _blink, _underline, _reverse, _italic);
406 
407 /*
408  * ++roman: I completely changed the attribute format for monochrome
409  * mode (!can_do_color). The formerly used MDA (monochrome display
410  * adapter) format didn't allow the combination of certain effects.
411  * Now the attribute is just a bit vector:
412  *  Bit 0..1: intensity (0..2)
413  *  Bit 2   : underline
414  *  Bit 3   : reverse
415  *  Bit 7   : blink
416  */
417 	{
418 	u8 a = _color;
419 	if (!vc->vc_can_do_color)
420 		return _intensity |
421 		       (_italic ? 2 : 0) |
422 		       (_underline ? 4 : 0) |
423 		       (_reverse ? 8 : 0) |
424 		       (_blink ? 0x80 : 0);
425 	if (_italic)
426 		a = (a & 0xF0) | vc->vc_itcolor;
427 	else if (_underline)
428 		a = (a & 0xf0) | vc->vc_ulcolor;
429 	else if (_intensity == 0)
430 		a = (a & 0xf0) | vc->vc_halfcolor;
431 	if (_reverse)
432 		a = ((a) & 0x88) | ((((a) >> 4) | ((a) << 4)) & 0x77);
433 	if (_blink)
434 		a ^= 0x80;
435 	if (_intensity == 2)
436 		a ^= 0x08;
437 	if (vc->vc_hi_font_mask == 0x100)
438 		a <<= 1;
439 	return a;
440 	}
441 }
442 
443 static void update_attr(struct vc_data *vc)
444 {
445 	vc->vc_attr = build_attr(vc, vc->vc_color, vc->vc_intensity,
446 	              vc->vc_blink, vc->vc_underline,
447 	              vc->vc_reverse ^ vc->vc_decscnm, vc->vc_italic);
448 	vc->vc_video_erase_char = (build_attr(vc, vc->vc_color, 1, vc->vc_blink, 0, vc->vc_decscnm, 0) << 8) | ' ';
449 }
450 
451 /* Note: inverting the screen twice should revert to the original state */
452 void invert_screen(struct vc_data *vc, int offset, int count, int viewed)
453 {
454 	unsigned short *p;
455 
456 	WARN_CONSOLE_UNLOCKED();
457 
458 	count /= 2;
459 	p = screenpos(vc, offset, viewed);
460 	if (vc->vc_sw->con_invert_region) {
461 		vc->vc_sw->con_invert_region(vc, p, count);
462 	} else {
463 		u16 *q = p;
464 		int cnt = count;
465 		u16 a;
466 
467 		if (!vc->vc_can_do_color) {
468 			while (cnt--) {
469 			    a = scr_readw(q);
470 			    a ^= 0x0800;
471 			    scr_writew(a, q);
472 			    q++;
473 			}
474 		} else if (vc->vc_hi_font_mask == 0x100) {
475 			while (cnt--) {
476 				a = scr_readw(q);
477 				a = ((a) & 0x11ff) | (((a) & 0xe000) >> 4) | (((a) & 0x0e00) << 4);
478 				scr_writew(a, q);
479 				q++;
480 			}
481 		} else {
482 			while (cnt--) {
483 				a = scr_readw(q);
484 				a = ((a) & 0x88ff) | (((a) & 0x7000) >> 4) | (((a) & 0x0700) << 4);
485 				scr_writew(a, q);
486 				q++;
487 			}
488 		}
489 	}
490 
491 	if (con_should_update(vc))
492 		do_update_region(vc, (unsigned long) p, count);
493 	notify_update(vc);
494 }
495 
496 /* used by selection: complement pointer position */
497 void complement_pos(struct vc_data *vc, int offset)
498 {
499 	static int old_offset = -1;
500 	static unsigned short old;
501 	static unsigned short oldx, oldy;
502 
503 	WARN_CONSOLE_UNLOCKED();
504 
505 	if (old_offset != -1 && old_offset >= 0 &&
506 	    old_offset < vc->vc_screenbuf_size) {
507 		scr_writew(old, screenpos(vc, old_offset, 1));
508 		if (con_should_update(vc))
509 			vc->vc_sw->con_putc(vc, old, oldy, oldx);
510 		notify_update(vc);
511 	}
512 
513 	old_offset = offset;
514 
515 	if (offset != -1 && offset >= 0 &&
516 	    offset < vc->vc_screenbuf_size) {
517 		unsigned short new;
518 		unsigned short *p;
519 		p = screenpos(vc, offset, 1);
520 		old = scr_readw(p);
521 		new = old ^ vc->vc_complement_mask;
522 		scr_writew(new, p);
523 		if (con_should_update(vc)) {
524 			oldx = (offset >> 1) % vc->vc_cols;
525 			oldy = (offset >> 1) / vc->vc_cols;
526 			vc->vc_sw->con_putc(vc, new, oldy, oldx);
527 		}
528 		notify_update(vc);
529 	}
530 }
531 
532 static void insert_char(struct vc_data *vc, unsigned int nr)
533 {
534 	unsigned short *p = (unsigned short *) vc->vc_pos;
535 
536 	scr_memmovew(p + nr, p, (vc->vc_cols - vc->vc_x - nr) * 2);
537 	scr_memsetw(p, vc->vc_video_erase_char, nr * 2);
538 	vc->vc_need_wrap = 0;
539 	if (con_should_update(vc))
540 		do_update_region(vc, (unsigned long) p,
541 			vc->vc_cols - vc->vc_x);
542 }
543 
544 static void delete_char(struct vc_data *vc, unsigned int nr)
545 {
546 	unsigned short *p = (unsigned short *) vc->vc_pos;
547 
548 	scr_memcpyw(p, p + nr, (vc->vc_cols - vc->vc_x - nr) * 2);
549 	scr_memsetw(p + vc->vc_cols - vc->vc_x - nr, vc->vc_video_erase_char,
550 			nr * 2);
551 	vc->vc_need_wrap = 0;
552 	if (con_should_update(vc))
553 		do_update_region(vc, (unsigned long) p,
554 			vc->vc_cols - vc->vc_x);
555 }
556 
557 static int softcursor_original = -1;
558 
559 static void add_softcursor(struct vc_data *vc)
560 {
561 	int i = scr_readw((u16 *) vc->vc_pos);
562 	u32 type = vc->vc_cursor_type;
563 
564 	if (! (type & 0x10)) return;
565 	if (softcursor_original != -1) return;
566 	softcursor_original = i;
567 	i |= ((type >> 8) & 0xff00 );
568 	i ^= ((type) & 0xff00 );
569 	if ((type & 0x20) && ((softcursor_original & 0x7000) == (i & 0x7000))) i ^= 0x7000;
570 	if ((type & 0x40) && ((i & 0x700) == ((i & 0x7000) >> 4))) i ^= 0x0700;
571 	scr_writew(i, (u16 *) vc->vc_pos);
572 	if (con_should_update(vc))
573 		vc->vc_sw->con_putc(vc, i, vc->vc_y, vc->vc_x);
574 }
575 
576 static void hide_softcursor(struct vc_data *vc)
577 {
578 	if (softcursor_original != -1) {
579 		scr_writew(softcursor_original, (u16 *)vc->vc_pos);
580 		if (con_should_update(vc))
581 			vc->vc_sw->con_putc(vc, softcursor_original,
582 					vc->vc_y, vc->vc_x);
583 		softcursor_original = -1;
584 	}
585 }
586 
587 static void hide_cursor(struct vc_data *vc)
588 {
589 	if (vc == sel_cons)
590 		clear_selection();
591 	vc->vc_sw->con_cursor(vc, CM_ERASE);
592 	hide_softcursor(vc);
593 }
594 
595 static void set_cursor(struct vc_data *vc)
596 {
597 	if (!con_is_fg(vc) || console_blanked || vc->vc_mode == KD_GRAPHICS)
598 		return;
599 	if (vc->vc_deccm) {
600 		if (vc == sel_cons)
601 			clear_selection();
602 		add_softcursor(vc);
603 		if ((vc->vc_cursor_type & 0x0f) != 1)
604 			vc->vc_sw->con_cursor(vc, CM_DRAW);
605 	} else
606 		hide_cursor(vc);
607 }
608 
609 static void set_origin(struct vc_data *vc)
610 {
611 	WARN_CONSOLE_UNLOCKED();
612 
613 	if (!con_is_visible(vc) ||
614 	    !vc->vc_sw->con_set_origin ||
615 	    !vc->vc_sw->con_set_origin(vc))
616 		vc->vc_origin = (unsigned long)vc->vc_screenbuf;
617 	vc->vc_visible_origin = vc->vc_origin;
618 	vc->vc_scr_end = vc->vc_origin + vc->vc_screenbuf_size;
619 	vc->vc_pos = vc->vc_origin + vc->vc_size_row * vc->vc_y + 2 * vc->vc_x;
620 }
621 
622 static void save_screen(struct vc_data *vc)
623 {
624 	WARN_CONSOLE_UNLOCKED();
625 
626 	if (vc->vc_sw->con_save_screen)
627 		vc->vc_sw->con_save_screen(vc);
628 }
629 
630 static void flush_scrollback(struct vc_data *vc)
631 {
632 	WARN_CONSOLE_UNLOCKED();
633 
634 	if (vc->vc_sw->con_flush_scrollback)
635 		vc->vc_sw->con_flush_scrollback(vc);
636 }
637 
638 /*
639  *	Redrawing of screen
640  */
641 
642 void clear_buffer_attributes(struct vc_data *vc)
643 {
644 	unsigned short *p = (unsigned short *)vc->vc_origin;
645 	int count = vc->vc_screenbuf_size / 2;
646 	int mask = vc->vc_hi_font_mask | 0xff;
647 
648 	for (; count > 0; count--, p++) {
649 		scr_writew((scr_readw(p)&mask) | (vc->vc_video_erase_char & ~mask), p);
650 	}
651 }
652 
653 void redraw_screen(struct vc_data *vc, int is_switch)
654 {
655 	int redraw = 0;
656 
657 	WARN_CONSOLE_UNLOCKED();
658 
659 	if (!vc) {
660 		/* strange ... */
661 		/* printk("redraw_screen: tty %d not allocated ??\n", new_console+1); */
662 		return;
663 	}
664 
665 	if (is_switch) {
666 		struct vc_data *old_vc = vc_cons[fg_console].d;
667 		if (old_vc == vc)
668 			return;
669 		if (!con_is_visible(vc))
670 			redraw = 1;
671 		*vc->vc_display_fg = vc;
672 		fg_console = vc->vc_num;
673 		hide_cursor(old_vc);
674 		if (!con_is_visible(old_vc)) {
675 			save_screen(old_vc);
676 			set_origin(old_vc);
677 		}
678 		if (tty0dev)
679 			sysfs_notify(&tty0dev->kobj, NULL, "active");
680 	} else {
681 		hide_cursor(vc);
682 		redraw = 1;
683 	}
684 
685 	if (redraw) {
686 		int update;
687 		int old_was_color = vc->vc_can_do_color;
688 
689 		set_origin(vc);
690 		update = vc->vc_sw->con_switch(vc);
691 		set_palette(vc);
692 		/*
693 		 * If console changed from mono<->color, the best we can do
694 		 * is to clear the buffer attributes. As it currently stands,
695 		 * rebuilding new attributes from the old buffer is not doable
696 		 * without overly complex code.
697 		 */
698 		if (old_was_color != vc->vc_can_do_color) {
699 			update_attr(vc);
700 			clear_buffer_attributes(vc);
701 		}
702 
703 		/* Forcibly update if we're panicing */
704 		if ((update && vc->vc_mode != KD_GRAPHICS) ||
705 		    vt_force_oops_output(vc))
706 			do_update_region(vc, vc->vc_origin, vc->vc_screenbuf_size / 2);
707 	}
708 	set_cursor(vc);
709 	if (is_switch) {
710 		set_leds();
711 		compute_shiftstate();
712 		notify_update(vc);
713 	}
714 }
715 
716 /*
717  *	Allocation, freeing and resizing of VTs.
718  */
719 
720 int vc_cons_allocated(unsigned int i)
721 {
722 	return (i < MAX_NR_CONSOLES && vc_cons[i].d);
723 }
724 
725 static void visual_init(struct vc_data *vc, int num, int init)
726 {
727 	/* ++Geert: vc->vc_sw->con_init determines console size */
728 	if (vc->vc_sw)
729 		module_put(vc->vc_sw->owner);
730 	vc->vc_sw = conswitchp;
731 #ifndef VT_SINGLE_DRIVER
732 	if (con_driver_map[num])
733 		vc->vc_sw = con_driver_map[num];
734 #endif
735 	__module_get(vc->vc_sw->owner);
736 	vc->vc_num = num;
737 	vc->vc_display_fg = &master_display_fg;
738 	if (vc->vc_uni_pagedir_loc)
739 		con_free_unimap(vc);
740 	vc->vc_uni_pagedir_loc = &vc->vc_uni_pagedir;
741 	vc->vc_uni_pagedir = NULL;
742 	vc->vc_hi_font_mask = 0;
743 	vc->vc_complement_mask = 0;
744 	vc->vc_can_do_color = 0;
745 	vc->vc_panic_force_write = false;
746 	vc->vc_cur_blink_ms = DEFAULT_CURSOR_BLINK_MS;
747 	vc->vc_sw->con_init(vc, init);
748 	if (!vc->vc_complement_mask)
749 		vc->vc_complement_mask = vc->vc_can_do_color ? 0x7700 : 0x0800;
750 	vc->vc_s_complement_mask = vc->vc_complement_mask;
751 	vc->vc_size_row = vc->vc_cols << 1;
752 	vc->vc_screenbuf_size = vc->vc_rows * vc->vc_size_row;
753 }
754 
755 int vc_allocate(unsigned int currcons)	/* return 0 on success */
756 {
757 	struct vt_notifier_param param;
758 	struct vc_data *vc;
759 
760 	WARN_CONSOLE_UNLOCKED();
761 
762 	if (currcons >= MAX_NR_CONSOLES)
763 		return -ENXIO;
764 
765 	if (vc_cons[currcons].d)
766 		return 0;
767 
768 	/* due to the granularity of kmalloc, we waste some memory here */
769 	/* the alloc is done in two steps, to optimize the common situation
770 	   of a 25x80 console (structsize=216, screenbuf_size=4000) */
771 	/* although the numbers above are not valid since long ago, the
772 	   point is still up-to-date and the comment still has its value
773 	   even if only as a historical artifact.  --mj, July 1998 */
774 	param.vc = vc = kzalloc(sizeof(struct vc_data), GFP_KERNEL);
775 	if (!vc)
776 		return -ENOMEM;
777 
778 	vc_cons[currcons].d = vc;
779 	tty_port_init(&vc->port);
780 	INIT_WORK(&vc_cons[currcons].SAK_work, vc_SAK);
781 
782 	visual_init(vc, currcons, 1);
783 
784 	if (!*vc->vc_uni_pagedir_loc)
785 		con_set_default_unimap(vc);
786 
787 	vc->vc_screenbuf = kzalloc(vc->vc_screenbuf_size, GFP_KERNEL);
788 	if (!vc->vc_screenbuf)
789 		goto err_free;
790 
791 	/* If no drivers have overridden us and the user didn't pass a
792 	   boot option, default to displaying the cursor */
793 	if (global_cursor_default == -1)
794 		global_cursor_default = 1;
795 
796 	vc_init(vc, vc->vc_rows, vc->vc_cols, 1);
797 	vcs_make_sysfs(currcons);
798 	atomic_notifier_call_chain(&vt_notifier_list, VT_ALLOCATE, &param);
799 
800 	return 0;
801 err_free:
802 	kfree(vc);
803 	vc_cons[currcons].d = NULL;
804 	return -ENOMEM;
805 }
806 
807 static inline int resize_screen(struct vc_data *vc, int width, int height,
808 				int user)
809 {
810 	/* Resizes the resolution of the display adapater */
811 	int err = 0;
812 
813 	if (vc->vc_mode != KD_GRAPHICS && vc->vc_sw->con_resize)
814 		err = vc->vc_sw->con_resize(vc, width, height, user);
815 
816 	return err;
817 }
818 
819 /*
820  * Change # of rows and columns (0 means unchanged/the size of fg_console)
821  * [this is to be used together with some user program
822  * like resize that changes the hardware videomode]
823  */
824 #define VC_RESIZE_MAXCOL (32767)
825 #define VC_RESIZE_MAXROW (32767)
826 
827 /**
828  *	vc_do_resize	-	resizing method for the tty
829  *	@tty: tty being resized
830  *	@real_tty: real tty (different to tty if a pty/tty pair)
831  *	@vc: virtual console private data
832  *	@cols: columns
833  *	@lines: lines
834  *
835  *	Resize a virtual console, clipping according to the actual constraints.
836  *	If the caller passes a tty structure then update the termios winsize
837  *	information and perform any necessary signal handling.
838  *
839  *	Caller must hold the console semaphore. Takes the termios rwsem and
840  *	ctrl_lock of the tty IFF a tty is passed.
841  */
842 
843 static int vc_do_resize(struct tty_struct *tty, struct vc_data *vc,
844 				unsigned int cols, unsigned int lines)
845 {
846 	unsigned long old_origin, new_origin, new_scr_end, rlth, rrem, err = 0;
847 	unsigned long end;
848 	unsigned int old_rows, old_row_size;
849 	unsigned int new_cols, new_rows, new_row_size, new_screen_size;
850 	unsigned int user;
851 	unsigned short *newscreen;
852 
853 	WARN_CONSOLE_UNLOCKED();
854 
855 	if (!vc)
856 		return -ENXIO;
857 
858 	user = vc->vc_resize_user;
859 	vc->vc_resize_user = 0;
860 
861 	if (cols > VC_RESIZE_MAXCOL || lines > VC_RESIZE_MAXROW)
862 		return -EINVAL;
863 
864 	new_cols = (cols ? cols : vc->vc_cols);
865 	new_rows = (lines ? lines : vc->vc_rows);
866 	new_row_size = new_cols << 1;
867 	new_screen_size = new_row_size * new_rows;
868 
869 	if (new_cols == vc->vc_cols && new_rows == vc->vc_rows)
870 		return 0;
871 
872 	if (new_screen_size > (4 << 20))
873 		return -EINVAL;
874 	newscreen = kzalloc(new_screen_size, GFP_USER);
875 	if (!newscreen)
876 		return -ENOMEM;
877 
878 	if (vc == sel_cons)
879 		clear_selection();
880 
881 	old_rows = vc->vc_rows;
882 	old_row_size = vc->vc_size_row;
883 
884 	err = resize_screen(vc, new_cols, new_rows, user);
885 	if (err) {
886 		kfree(newscreen);
887 		return err;
888 	}
889 
890 	vc->vc_rows = new_rows;
891 	vc->vc_cols = new_cols;
892 	vc->vc_size_row = new_row_size;
893 	vc->vc_screenbuf_size = new_screen_size;
894 
895 	rlth = min(old_row_size, new_row_size);
896 	rrem = new_row_size - rlth;
897 	old_origin = vc->vc_origin;
898 	new_origin = (long) newscreen;
899 	new_scr_end = new_origin + new_screen_size;
900 
901 	if (vc->vc_y > new_rows) {
902 		if (old_rows - vc->vc_y < new_rows) {
903 			/*
904 			 * Cursor near the bottom, copy contents from the
905 			 * bottom of buffer
906 			 */
907 			old_origin += (old_rows - new_rows) * old_row_size;
908 		} else {
909 			/*
910 			 * Cursor is in no man's land, copy 1/2 screenful
911 			 * from the top and bottom of cursor position
912 			 */
913 			old_origin += (vc->vc_y - new_rows/2) * old_row_size;
914 		}
915 	}
916 
917 	end = old_origin + old_row_size * min(old_rows, new_rows);
918 
919 	update_attr(vc);
920 
921 	while (old_origin < end) {
922 		scr_memcpyw((unsigned short *) new_origin,
923 			    (unsigned short *) old_origin, rlth);
924 		if (rrem)
925 			scr_memsetw((void *)(new_origin + rlth),
926 				    vc->vc_video_erase_char, rrem);
927 		old_origin += old_row_size;
928 		new_origin += new_row_size;
929 	}
930 	if (new_scr_end > new_origin)
931 		scr_memsetw((void *)new_origin, vc->vc_video_erase_char,
932 			    new_scr_end - new_origin);
933 	kfree(vc->vc_screenbuf);
934 	vc->vc_screenbuf = newscreen;
935 	vc->vc_screenbuf_size = new_screen_size;
936 	set_origin(vc);
937 
938 	/* do part of a reset_terminal() */
939 	vc->vc_top = 0;
940 	vc->vc_bottom = vc->vc_rows;
941 	gotoxy(vc, vc->vc_x, vc->vc_y);
942 	save_cur(vc);
943 
944 	if (tty) {
945 		/* Rewrite the requested winsize data with the actual
946 		   resulting sizes */
947 		struct winsize ws;
948 		memset(&ws, 0, sizeof(ws));
949 		ws.ws_row = vc->vc_rows;
950 		ws.ws_col = vc->vc_cols;
951 		ws.ws_ypixel = vc->vc_scan_lines;
952 		tty_do_resize(tty, &ws);
953 	}
954 
955 	if (con_is_visible(vc))
956 		update_screen(vc);
957 	vt_event_post(VT_EVENT_RESIZE, vc->vc_num, vc->vc_num);
958 	return err;
959 }
960 
961 /**
962  *	vc_resize		-	resize a VT
963  *	@vc: virtual console
964  *	@cols: columns
965  *	@rows: rows
966  *
967  *	Resize a virtual console as seen from the console end of things. We
968  *	use the common vc_do_resize methods to update the structures. The
969  *	caller must hold the console sem to protect console internals and
970  *	vc->port.tty
971  */
972 
973 int vc_resize(struct vc_data *vc, unsigned int cols, unsigned int rows)
974 {
975 	return vc_do_resize(vc->port.tty, vc, cols, rows);
976 }
977 
978 /**
979  *	vt_resize		-	resize a VT
980  *	@tty: tty to resize
981  *	@ws: winsize attributes
982  *
983  *	Resize a virtual terminal. This is called by the tty layer as we
984  *	register our own handler for resizing. The mutual helper does all
985  *	the actual work.
986  *
987  *	Takes the console sem and the called methods then take the tty
988  *	termios_rwsem and the tty ctrl_lock in that order.
989  */
990 static int vt_resize(struct tty_struct *tty, struct winsize *ws)
991 {
992 	struct vc_data *vc = tty->driver_data;
993 	int ret;
994 
995 	console_lock();
996 	ret = vc_do_resize(tty, vc, ws->ws_col, ws->ws_row);
997 	console_unlock();
998 	return ret;
999 }
1000 
1001 struct vc_data *vc_deallocate(unsigned int currcons)
1002 {
1003 	struct vc_data *vc = NULL;
1004 
1005 	WARN_CONSOLE_UNLOCKED();
1006 
1007 	if (vc_cons_allocated(currcons)) {
1008 		struct vt_notifier_param param;
1009 
1010 		param.vc = vc = vc_cons[currcons].d;
1011 		atomic_notifier_call_chain(&vt_notifier_list, VT_DEALLOCATE, &param);
1012 		vcs_remove_sysfs(currcons);
1013 		vc->vc_sw->con_deinit(vc);
1014 		put_pid(vc->vt_pid);
1015 		module_put(vc->vc_sw->owner);
1016 		kfree(vc->vc_screenbuf);
1017 		vc_cons[currcons].d = NULL;
1018 	}
1019 	return vc;
1020 }
1021 
1022 /*
1023  *	VT102 emulator
1024  */
1025 
1026 #define set_kbd(vc, x)	vt_set_kbd_mode_bit((vc)->vc_num, (x))
1027 #define clr_kbd(vc, x)	vt_clr_kbd_mode_bit((vc)->vc_num, (x))
1028 #define is_kbd(vc, x)	vt_get_kbd_mode_bit((vc)->vc_num, (x))
1029 
1030 #define decarm		VC_REPEAT
1031 #define decckm		VC_CKMODE
1032 #define kbdapplic	VC_APPLIC
1033 #define lnm		VC_CRLF
1034 
1035 /*
1036  * this is what the terminal answers to a ESC-Z or csi0c query.
1037  */
1038 #define VT100ID "\033[?1;2c"
1039 #define VT102ID "\033[?6c"
1040 
1041 const unsigned char color_table[] = { 0, 4, 2, 6, 1, 5, 3, 7,
1042 				       8,12,10,14, 9,13,11,15 };
1043 
1044 /* the default colour table, for VGA+ colour systems */
1045 unsigned char default_red[] = {
1046 	0x00, 0xaa, 0x00, 0xaa, 0x00, 0xaa, 0x00, 0xaa,
1047 	0x55, 0xff, 0x55, 0xff, 0x55, 0xff, 0x55, 0xff
1048 };
1049 module_param_array(default_red, byte, NULL, S_IRUGO | S_IWUSR);
1050 
1051 unsigned char default_grn[] = {
1052 	0x00, 0x00, 0xaa, 0x55, 0x00, 0x00, 0xaa, 0xaa,
1053 	0x55, 0x55, 0xff, 0xff, 0x55, 0x55, 0xff, 0xff
1054 };
1055 module_param_array(default_grn, byte, NULL, S_IRUGO | S_IWUSR);
1056 
1057 unsigned char default_blu[] = {
1058 	0x00, 0x00, 0x00, 0x00, 0xaa, 0xaa, 0xaa, 0xaa,
1059 	0x55, 0x55, 0x55, 0x55, 0xff, 0xff, 0xff, 0xff
1060 };
1061 module_param_array(default_blu, byte, NULL, S_IRUGO | S_IWUSR);
1062 
1063 /*
1064  * gotoxy() must verify all boundaries, because the arguments
1065  * might also be negative. If the given position is out of
1066  * bounds, the cursor is placed at the nearest margin.
1067  */
1068 static void gotoxy(struct vc_data *vc, int new_x, int new_y)
1069 {
1070 	int min_y, max_y;
1071 
1072 	if (new_x < 0)
1073 		vc->vc_x = 0;
1074 	else {
1075 		if (new_x >= vc->vc_cols)
1076 			vc->vc_x = vc->vc_cols - 1;
1077 		else
1078 			vc->vc_x = new_x;
1079 	}
1080 
1081  	if (vc->vc_decom) {
1082 		min_y = vc->vc_top;
1083 		max_y = vc->vc_bottom;
1084 	} else {
1085 		min_y = 0;
1086 		max_y = vc->vc_rows;
1087 	}
1088 	if (new_y < min_y)
1089 		vc->vc_y = min_y;
1090 	else if (new_y >= max_y)
1091 		vc->vc_y = max_y - 1;
1092 	else
1093 		vc->vc_y = new_y;
1094 	vc->vc_pos = vc->vc_origin + vc->vc_y * vc->vc_size_row + (vc->vc_x<<1);
1095 	vc->vc_need_wrap = 0;
1096 }
1097 
1098 /* for absolute user moves, when decom is set */
1099 static void gotoxay(struct vc_data *vc, int new_x, int new_y)
1100 {
1101 	gotoxy(vc, new_x, vc->vc_decom ? (vc->vc_top + new_y) : new_y);
1102 }
1103 
1104 void scrollback(struct vc_data *vc)
1105 {
1106 	scrolldelta(-(vc->vc_rows / 2));
1107 }
1108 
1109 void scrollfront(struct vc_data *vc, int lines)
1110 {
1111 	if (!lines)
1112 		lines = vc->vc_rows / 2;
1113 	scrolldelta(lines);
1114 }
1115 
1116 static void lf(struct vc_data *vc)
1117 {
1118     	/* don't scroll if above bottom of scrolling region, or
1119 	 * if below scrolling region
1120 	 */
1121     	if (vc->vc_y + 1 == vc->vc_bottom)
1122 		con_scroll(vc, vc->vc_top, vc->vc_bottom, SM_UP, 1);
1123 	else if (vc->vc_y < vc->vc_rows - 1) {
1124 	    	vc->vc_y++;
1125 		vc->vc_pos += vc->vc_size_row;
1126 	}
1127 	vc->vc_need_wrap = 0;
1128 	notify_write(vc, '\n');
1129 }
1130 
1131 static void ri(struct vc_data *vc)
1132 {
1133     	/* don't scroll if below top of scrolling region, or
1134 	 * if above scrolling region
1135 	 */
1136 	if (vc->vc_y == vc->vc_top)
1137 		con_scroll(vc, vc->vc_top, vc->vc_bottom, SM_DOWN, 1);
1138 	else if (vc->vc_y > 0) {
1139 		vc->vc_y--;
1140 		vc->vc_pos -= vc->vc_size_row;
1141 	}
1142 	vc->vc_need_wrap = 0;
1143 }
1144 
1145 static inline void cr(struct vc_data *vc)
1146 {
1147 	vc->vc_pos -= vc->vc_x << 1;
1148 	vc->vc_need_wrap = vc->vc_x = 0;
1149 	notify_write(vc, '\r');
1150 }
1151 
1152 static inline void bs(struct vc_data *vc)
1153 {
1154 	if (vc->vc_x) {
1155 		vc->vc_pos -= 2;
1156 		vc->vc_x--;
1157 		vc->vc_need_wrap = 0;
1158 		notify_write(vc, '\b');
1159 	}
1160 }
1161 
1162 static inline void del(struct vc_data *vc)
1163 {
1164 	/* ignored */
1165 }
1166 
1167 static void csi_J(struct vc_data *vc, int vpar)
1168 {
1169 	unsigned int count;
1170 	unsigned short * start;
1171 
1172 	switch (vpar) {
1173 		case 0:	/* erase from cursor to end of display */
1174 			count = (vc->vc_scr_end - vc->vc_pos) >> 1;
1175 			start = (unsigned short *)vc->vc_pos;
1176 			break;
1177 		case 1:	/* erase from start to cursor */
1178 			count = ((vc->vc_pos - vc->vc_origin) >> 1) + 1;
1179 			start = (unsigned short *)vc->vc_origin;
1180 			break;
1181 		case 2: /* erase whole display */
1182 		case 3: /* (and scrollback buffer later) */
1183 			count = vc->vc_cols * vc->vc_rows;
1184 			start = (unsigned short *)vc->vc_origin;
1185 			break;
1186 		default:
1187 			return;
1188 	}
1189 	scr_memsetw(start, vc->vc_video_erase_char, 2 * count);
1190 	if (vpar == 3) {
1191 		set_origin(vc);
1192 		flush_scrollback(vc);
1193 		if (con_is_visible(vc))
1194 			update_screen(vc);
1195 	} else if (con_should_update(vc))
1196 		do_update_region(vc, (unsigned long) start, count);
1197 	vc->vc_need_wrap = 0;
1198 }
1199 
1200 static void csi_K(struct vc_data *vc, int vpar)
1201 {
1202 	unsigned int count;
1203 	unsigned short * start;
1204 
1205 	switch (vpar) {
1206 		case 0:	/* erase from cursor to end of line */
1207 			count = vc->vc_cols - vc->vc_x;
1208 			start = (unsigned short *)vc->vc_pos;
1209 			break;
1210 		case 1:	/* erase from start of line to cursor */
1211 			start = (unsigned short *)(vc->vc_pos - (vc->vc_x << 1));
1212 			count = vc->vc_x + 1;
1213 			break;
1214 		case 2: /* erase whole line */
1215 			start = (unsigned short *)(vc->vc_pos - (vc->vc_x << 1));
1216 			count = vc->vc_cols;
1217 			break;
1218 		default:
1219 			return;
1220 	}
1221 	scr_memsetw(start, vc->vc_video_erase_char, 2 * count);
1222 	vc->vc_need_wrap = 0;
1223 	if (con_should_update(vc))
1224 		do_update_region(vc, (unsigned long) start, count);
1225 }
1226 
1227 static void csi_X(struct vc_data *vc, int vpar) /* erase the following vpar positions */
1228 {					  /* not vt100? */
1229 	int count;
1230 
1231 	if (!vpar)
1232 		vpar++;
1233 	count = (vpar > vc->vc_cols - vc->vc_x) ? (vc->vc_cols - vc->vc_x) : vpar;
1234 
1235 	scr_memsetw((unsigned short *)vc->vc_pos, vc->vc_video_erase_char, 2 * count);
1236 	if (con_should_update(vc))
1237 		vc->vc_sw->con_clear(vc, vc->vc_y, vc->vc_x, 1, count);
1238 	vc->vc_need_wrap = 0;
1239 }
1240 
1241 static void default_attr(struct vc_data *vc)
1242 {
1243 	vc->vc_intensity = 1;
1244 	vc->vc_italic = 0;
1245 	vc->vc_underline = 0;
1246 	vc->vc_reverse = 0;
1247 	vc->vc_blink = 0;
1248 	vc->vc_color = vc->vc_def_color;
1249 }
1250 
1251 struct rgb { u8 r; u8 g; u8 b; };
1252 
1253 static void rgb_from_256(int i, struct rgb *c)
1254 {
1255 	if (i < 8) {            /* Standard colours. */
1256 		c->r = i&1 ? 0xaa : 0x00;
1257 		c->g = i&2 ? 0xaa : 0x00;
1258 		c->b = i&4 ? 0xaa : 0x00;
1259 	} else if (i < 16) {
1260 		c->r = i&1 ? 0xff : 0x55;
1261 		c->g = i&2 ? 0xff : 0x55;
1262 		c->b = i&4 ? 0xff : 0x55;
1263 	} else if (i < 232) {   /* 6x6x6 colour cube. */
1264 		c->r = (i - 16) / 36 * 85 / 2;
1265 		c->g = (i - 16) / 6 % 6 * 85 / 2;
1266 		c->b = (i - 16) % 6 * 85 / 2;
1267 	} else                  /* Grayscale ramp. */
1268 		c->r = c->g = c->b = i * 10 - 2312;
1269 }
1270 
1271 static void rgb_foreground(struct vc_data *vc, const struct rgb *c)
1272 {
1273 	u8 hue = 0, max = max3(c->r, c->g, c->b);
1274 
1275 	if (c->r > max / 2)
1276 		hue |= 4;
1277 	if (c->g > max / 2)
1278 		hue |= 2;
1279 	if (c->b > max / 2)
1280 		hue |= 1;
1281 
1282 	if (hue == 7 && max <= 0x55) {
1283 		hue = 0;
1284 		vc->vc_intensity = 2;
1285 	} else if (max > 0xaa)
1286 		vc->vc_intensity = 2;
1287 	else
1288 		vc->vc_intensity = 1;
1289 
1290 	vc->vc_color = (vc->vc_color & 0xf0) | hue;
1291 }
1292 
1293 static void rgb_background(struct vc_data *vc, const struct rgb *c)
1294 {
1295 	/* For backgrounds, err on the dark side. */
1296 	vc->vc_color = (vc->vc_color & 0x0f)
1297 		| (c->r&0x80) >> 1 | (c->g&0x80) >> 2 | (c->b&0x80) >> 3;
1298 }
1299 
1300 /*
1301  * ITU T.416 Higher colour modes. They break the usual properties of SGR codes
1302  * and thus need to be detected and ignored by hand. Strictly speaking, that
1303  * standard also wants : rather than ; as separators, contrary to ECMA-48, but
1304  * no one produces such codes and almost no one accepts them.
1305  *
1306  * Subcommands 3 (CMY) and 4 (CMYK) are so insane there's no point in
1307  * supporting them.
1308  */
1309 static int vc_t416_color(struct vc_data *vc, int i,
1310 		void(*set_color)(struct vc_data *vc, const struct rgb *c))
1311 {
1312 	struct rgb c;
1313 
1314 	i++;
1315 	if (i > vc->vc_npar)
1316 		return i;
1317 
1318 	if (vc->vc_par[i] == 5 && i + 1 <= vc->vc_npar) {
1319 		/* 256 colours */
1320 		i++;
1321 		rgb_from_256(vc->vc_par[i], &c);
1322 	} else if (vc->vc_par[i] == 2 && i + 3 <= vc->vc_npar) {
1323 		/* 24 bit */
1324 		c.r = vc->vc_par[i + 1];
1325 		c.g = vc->vc_par[i + 2];
1326 		c.b = vc->vc_par[i + 3];
1327 		i += 3;
1328 	} else
1329 		return i;
1330 
1331 	set_color(vc, &c);
1332 
1333 	return i;
1334 }
1335 
1336 /* console_lock is held */
1337 static void csi_m(struct vc_data *vc)
1338 {
1339 	int i;
1340 
1341 	for (i = 0; i <= vc->vc_npar; i++)
1342 		switch (vc->vc_par[i]) {
1343 		case 0:	/* all attributes off */
1344 			default_attr(vc);
1345 			break;
1346 		case 1:
1347 			vc->vc_intensity = 2;
1348 			break;
1349 		case 2:
1350 			vc->vc_intensity = 0;
1351 			break;
1352 		case 3:
1353 			vc->vc_italic = 1;
1354 			break;
1355 		case 21:
1356 			/*
1357 			 * No console drivers support double underline, so
1358 			 * convert it to a single underline.
1359 			 */
1360 		case 4:
1361 			vc->vc_underline = 1;
1362 			break;
1363 		case 5:
1364 			vc->vc_blink = 1;
1365 			break;
1366 		case 7:
1367 			vc->vc_reverse = 1;
1368 			break;
1369 		case 10: /* ANSI X3.64-1979 (SCO-ish?)
1370 			  * Select primary font, don't display control chars if
1371 			  * defined, don't set bit 8 on output.
1372 			  */
1373 			vc->vc_translate = set_translate(vc->vc_charset == 0
1374 					? vc->vc_G0_charset
1375 					: vc->vc_G1_charset, vc);
1376 			vc->vc_disp_ctrl = 0;
1377 			vc->vc_toggle_meta = 0;
1378 			break;
1379 		case 11: /* ANSI X3.64-1979 (SCO-ish?)
1380 			  * Select first alternate font, lets chars < 32 be
1381 			  * displayed as ROM chars.
1382 			  */
1383 			vc->vc_translate = set_translate(IBMPC_MAP, vc);
1384 			vc->vc_disp_ctrl = 1;
1385 			vc->vc_toggle_meta = 0;
1386 			break;
1387 		case 12: /* ANSI X3.64-1979 (SCO-ish?)
1388 			  * Select second alternate font, toggle high bit
1389 			  * before displaying as ROM char.
1390 			  */
1391 			vc->vc_translate = set_translate(IBMPC_MAP, vc);
1392 			vc->vc_disp_ctrl = 1;
1393 			vc->vc_toggle_meta = 1;
1394 			break;
1395 		case 22:
1396 			vc->vc_intensity = 1;
1397 			break;
1398 		case 23:
1399 			vc->vc_italic = 0;
1400 			break;
1401 		case 24:
1402 			vc->vc_underline = 0;
1403 			break;
1404 		case 25:
1405 			vc->vc_blink = 0;
1406 			break;
1407 		case 27:
1408 			vc->vc_reverse = 0;
1409 			break;
1410 		case 38:
1411 			i = vc_t416_color(vc, i, rgb_foreground);
1412 			break;
1413 		case 48:
1414 			i = vc_t416_color(vc, i, rgb_background);
1415 			break;
1416 		case 39:
1417 			vc->vc_color = (vc->vc_def_color & 0x0f) |
1418 				(vc->vc_color & 0xf0);
1419 			break;
1420 		case 49:
1421 			vc->vc_color = (vc->vc_def_color & 0xf0) |
1422 				(vc->vc_color & 0x0f);
1423 			break;
1424 		default:
1425 			if (vc->vc_par[i] >= 90 && vc->vc_par[i] <= 107) {
1426 				if (vc->vc_par[i] < 100)
1427 					vc->vc_intensity = 2;
1428 				vc->vc_par[i] -= 60;
1429 			}
1430 			if (vc->vc_par[i] >= 30 && vc->vc_par[i] <= 37)
1431 				vc->vc_color = color_table[vc->vc_par[i] - 30]
1432 					| (vc->vc_color & 0xf0);
1433 			else if (vc->vc_par[i] >= 40 && vc->vc_par[i] <= 47)
1434 				vc->vc_color = (color_table[vc->vc_par[i] - 40] << 4)
1435 					| (vc->vc_color & 0x0f);
1436 			break;
1437 		}
1438 	update_attr(vc);
1439 }
1440 
1441 static void respond_string(const char *p, struct tty_port *port)
1442 {
1443 	while (*p) {
1444 		tty_insert_flip_char(port, *p, 0);
1445 		p++;
1446 	}
1447 	tty_schedule_flip(port);
1448 }
1449 
1450 static void cursor_report(struct vc_data *vc, struct tty_struct *tty)
1451 {
1452 	char buf[40];
1453 
1454 	sprintf(buf, "\033[%d;%dR", vc->vc_y + (vc->vc_decom ? vc->vc_top + 1 : 1), vc->vc_x + 1);
1455 	respond_string(buf, tty->port);
1456 }
1457 
1458 static inline void status_report(struct tty_struct *tty)
1459 {
1460 	respond_string("\033[0n", tty->port);	/* Terminal ok */
1461 }
1462 
1463 static inline void respond_ID(struct tty_struct *tty)
1464 {
1465 	respond_string(VT102ID, tty->port);
1466 }
1467 
1468 void mouse_report(struct tty_struct *tty, int butt, int mrx, int mry)
1469 {
1470 	char buf[8];
1471 
1472 	sprintf(buf, "\033[M%c%c%c", (char)(' ' + butt), (char)('!' + mrx),
1473 		(char)('!' + mry));
1474 	respond_string(buf, tty->port);
1475 }
1476 
1477 /* invoked via ioctl(TIOCLINUX) and through set_selection */
1478 int mouse_reporting(void)
1479 {
1480 	return vc_cons[fg_console].d->vc_report_mouse;
1481 }
1482 
1483 /* console_lock is held */
1484 static void set_mode(struct vc_data *vc, int on_off)
1485 {
1486 	int i;
1487 
1488 	for (i = 0; i <= vc->vc_npar; i++)
1489 		if (vc->vc_ques) {
1490 			switch(vc->vc_par[i]) {	/* DEC private modes set/reset */
1491 			case 1:			/* Cursor keys send ^[Ox/^[[x */
1492 				if (on_off)
1493 					set_kbd(vc, decckm);
1494 				else
1495 					clr_kbd(vc, decckm);
1496 				break;
1497 			case 3:	/* 80/132 mode switch unimplemented */
1498 #if 0
1499 				vc_resize(deccolm ? 132 : 80, vc->vc_rows);
1500 				/* this alone does not suffice; some user mode
1501 				   utility has to change the hardware regs */
1502 #endif
1503 				break;
1504 			case 5:			/* Inverted screen on/off */
1505 				if (vc->vc_decscnm != on_off) {
1506 					vc->vc_decscnm = on_off;
1507 					invert_screen(vc, 0, vc->vc_screenbuf_size, 0);
1508 					update_attr(vc);
1509 				}
1510 				break;
1511 			case 6:			/* Origin relative/absolute */
1512 				vc->vc_decom = on_off;
1513 				gotoxay(vc, 0, 0);
1514 				break;
1515 			case 7:			/* Autowrap on/off */
1516 				vc->vc_decawm = on_off;
1517 				break;
1518 			case 8:			/* Autorepeat on/off */
1519 				if (on_off)
1520 					set_kbd(vc, decarm);
1521 				else
1522 					clr_kbd(vc, decarm);
1523 				break;
1524 			case 9:
1525 				vc->vc_report_mouse = on_off ? 1 : 0;
1526 				break;
1527 			case 25:		/* Cursor on/off */
1528 				vc->vc_deccm = on_off;
1529 				break;
1530 			case 1000:
1531 				vc->vc_report_mouse = on_off ? 2 : 0;
1532 				break;
1533 			}
1534 		} else {
1535 			switch(vc->vc_par[i]) {	/* ANSI modes set/reset */
1536 			case 3:			/* Monitor (display ctrls) */
1537 				vc->vc_disp_ctrl = on_off;
1538 				break;
1539 			case 4:			/* Insert Mode on/off */
1540 				vc->vc_decim = on_off;
1541 				break;
1542 			case 20:		/* Lf, Enter == CrLf/Lf */
1543 				if (on_off)
1544 					set_kbd(vc, lnm);
1545 				else
1546 					clr_kbd(vc, lnm);
1547 				break;
1548 			}
1549 		}
1550 }
1551 
1552 /* console_lock is held */
1553 static void setterm_command(struct vc_data *vc)
1554 {
1555 	switch(vc->vc_par[0]) {
1556 		case 1:	/* set color for underline mode */
1557 			if (vc->vc_can_do_color &&
1558 					vc->vc_par[1] < 16) {
1559 				vc->vc_ulcolor = color_table[vc->vc_par[1]];
1560 				if (vc->vc_underline)
1561 					update_attr(vc);
1562 			}
1563 			break;
1564 		case 2:	/* set color for half intensity mode */
1565 			if (vc->vc_can_do_color &&
1566 					vc->vc_par[1] < 16) {
1567 				vc->vc_halfcolor = color_table[vc->vc_par[1]];
1568 				if (vc->vc_intensity == 0)
1569 					update_attr(vc);
1570 			}
1571 			break;
1572 		case 8:	/* store colors as defaults */
1573 			vc->vc_def_color = vc->vc_attr;
1574 			if (vc->vc_hi_font_mask == 0x100)
1575 				vc->vc_def_color >>= 1;
1576 			default_attr(vc);
1577 			update_attr(vc);
1578 			break;
1579 		case 9:	/* set blanking interval */
1580 			blankinterval = ((vc->vc_par[1] < 60) ? vc->vc_par[1] : 60) * 60;
1581 			poke_blanked_console();
1582 			break;
1583 		case 10: /* set bell frequency in Hz */
1584 			if (vc->vc_npar >= 1)
1585 				vc->vc_bell_pitch = vc->vc_par[1];
1586 			else
1587 				vc->vc_bell_pitch = DEFAULT_BELL_PITCH;
1588 			break;
1589 		case 11: /* set bell duration in msec */
1590 			if (vc->vc_npar >= 1)
1591 				vc->vc_bell_duration = (vc->vc_par[1] < 2000) ?
1592 					msecs_to_jiffies(vc->vc_par[1]) : 0;
1593 			else
1594 				vc->vc_bell_duration = DEFAULT_BELL_DURATION;
1595 			break;
1596 		case 12: /* bring specified console to the front */
1597 			if (vc->vc_par[1] >= 1 && vc_cons_allocated(vc->vc_par[1] - 1))
1598 				set_console(vc->vc_par[1] - 1);
1599 			break;
1600 		case 13: /* unblank the screen */
1601 			poke_blanked_console();
1602 			break;
1603 		case 14: /* set vesa powerdown interval */
1604 			vesa_off_interval = ((vc->vc_par[1] < 60) ? vc->vc_par[1] : 60) * 60 * HZ;
1605 			break;
1606 		case 15: /* activate the previous console */
1607 			set_console(last_console);
1608 			break;
1609 		case 16: /* set cursor blink duration in msec */
1610 			if (vc->vc_npar >= 1 && vc->vc_par[1] >= 50 &&
1611 					vc->vc_par[1] <= USHRT_MAX)
1612 				vc->vc_cur_blink_ms = vc->vc_par[1];
1613 			else
1614 				vc->vc_cur_blink_ms = DEFAULT_CURSOR_BLINK_MS;
1615 			break;
1616 	}
1617 }
1618 
1619 /* console_lock is held */
1620 static void csi_at(struct vc_data *vc, unsigned int nr)
1621 {
1622 	if (nr > vc->vc_cols - vc->vc_x)
1623 		nr = vc->vc_cols - vc->vc_x;
1624 	else if (!nr)
1625 		nr = 1;
1626 	insert_char(vc, nr);
1627 }
1628 
1629 /* console_lock is held */
1630 static void csi_L(struct vc_data *vc, unsigned int nr)
1631 {
1632 	if (nr > vc->vc_rows - vc->vc_y)
1633 		nr = vc->vc_rows - vc->vc_y;
1634 	else if (!nr)
1635 		nr = 1;
1636 	con_scroll(vc, vc->vc_y, vc->vc_bottom, SM_DOWN, nr);
1637 	vc->vc_need_wrap = 0;
1638 }
1639 
1640 /* console_lock is held */
1641 static void csi_P(struct vc_data *vc, unsigned int nr)
1642 {
1643 	if (nr > vc->vc_cols - vc->vc_x)
1644 		nr = vc->vc_cols - vc->vc_x;
1645 	else if (!nr)
1646 		nr = 1;
1647 	delete_char(vc, nr);
1648 }
1649 
1650 /* console_lock is held */
1651 static void csi_M(struct vc_data *vc, unsigned int nr)
1652 {
1653 	if (nr > vc->vc_rows - vc->vc_y)
1654 		nr = vc->vc_rows - vc->vc_y;
1655 	else if (!nr)
1656 		nr=1;
1657 	con_scroll(vc, vc->vc_y, vc->vc_bottom, SM_UP, nr);
1658 	vc->vc_need_wrap = 0;
1659 }
1660 
1661 /* console_lock is held (except via vc_init->reset_terminal */
1662 static void save_cur(struct vc_data *vc)
1663 {
1664 	vc->vc_saved_x		= vc->vc_x;
1665 	vc->vc_saved_y		= vc->vc_y;
1666 	vc->vc_s_intensity	= vc->vc_intensity;
1667 	vc->vc_s_italic         = vc->vc_italic;
1668 	vc->vc_s_underline	= vc->vc_underline;
1669 	vc->vc_s_blink		= vc->vc_blink;
1670 	vc->vc_s_reverse	= vc->vc_reverse;
1671 	vc->vc_s_charset	= vc->vc_charset;
1672 	vc->vc_s_color		= vc->vc_color;
1673 	vc->vc_saved_G0		= vc->vc_G0_charset;
1674 	vc->vc_saved_G1		= vc->vc_G1_charset;
1675 }
1676 
1677 /* console_lock is held */
1678 static void restore_cur(struct vc_data *vc)
1679 {
1680 	gotoxy(vc, vc->vc_saved_x, vc->vc_saved_y);
1681 	vc->vc_intensity	= vc->vc_s_intensity;
1682 	vc->vc_italic		= vc->vc_s_italic;
1683 	vc->vc_underline	= vc->vc_s_underline;
1684 	vc->vc_blink		= vc->vc_s_blink;
1685 	vc->vc_reverse		= vc->vc_s_reverse;
1686 	vc->vc_charset		= vc->vc_s_charset;
1687 	vc->vc_color		= vc->vc_s_color;
1688 	vc->vc_G0_charset	= vc->vc_saved_G0;
1689 	vc->vc_G1_charset	= vc->vc_saved_G1;
1690 	vc->vc_translate	= set_translate(vc->vc_charset ? vc->vc_G1_charset : vc->vc_G0_charset, vc);
1691 	update_attr(vc);
1692 	vc->vc_need_wrap = 0;
1693 }
1694 
1695 enum { ESnormal, ESesc, ESsquare, ESgetpars, ESfunckey,
1696 	EShash, ESsetG0, ESsetG1, ESpercent, ESignore, ESnonstd,
1697 	ESpalette, ESosc };
1698 
1699 /* console_lock is held (except via vc_init()) */
1700 static void reset_terminal(struct vc_data *vc, int do_clear)
1701 {
1702 	vc->vc_top		= 0;
1703 	vc->vc_bottom		= vc->vc_rows;
1704 	vc->vc_state		= ESnormal;
1705 	vc->vc_ques		= 0;
1706 	vc->vc_translate	= set_translate(LAT1_MAP, vc);
1707 	vc->vc_G0_charset	= LAT1_MAP;
1708 	vc->vc_G1_charset	= GRAF_MAP;
1709 	vc->vc_charset		= 0;
1710 	vc->vc_need_wrap	= 0;
1711 	vc->vc_report_mouse	= 0;
1712 	vc->vc_utf              = default_utf8;
1713 	vc->vc_utf_count	= 0;
1714 
1715 	vc->vc_disp_ctrl	= 0;
1716 	vc->vc_toggle_meta	= 0;
1717 
1718 	vc->vc_decscnm		= 0;
1719 	vc->vc_decom		= 0;
1720 	vc->vc_decawm		= 1;
1721 	vc->vc_deccm		= global_cursor_default;
1722 	vc->vc_decim		= 0;
1723 
1724 	vt_reset_keyboard(vc->vc_num);
1725 
1726 	vc->vc_cursor_type = cur_default;
1727 	vc->vc_complement_mask = vc->vc_s_complement_mask;
1728 
1729 	default_attr(vc);
1730 	update_attr(vc);
1731 
1732 	vc->vc_tab_stop[0]	=
1733 	vc->vc_tab_stop[1]	=
1734 	vc->vc_tab_stop[2]	=
1735 	vc->vc_tab_stop[3]	=
1736 	vc->vc_tab_stop[4]	=
1737 	vc->vc_tab_stop[5]	=
1738 	vc->vc_tab_stop[6]	=
1739 	vc->vc_tab_stop[7]	= 0x01010101;
1740 
1741 	vc->vc_bell_pitch = DEFAULT_BELL_PITCH;
1742 	vc->vc_bell_duration = DEFAULT_BELL_DURATION;
1743 	vc->vc_cur_blink_ms = DEFAULT_CURSOR_BLINK_MS;
1744 
1745 	gotoxy(vc, 0, 0);
1746 	save_cur(vc);
1747 	if (do_clear)
1748 	    csi_J(vc, 2);
1749 }
1750 
1751 /* console_lock is held */
1752 static void do_con_trol(struct tty_struct *tty, struct vc_data *vc, int c)
1753 {
1754 	/*
1755 	 *  Control characters can be used in the _middle_
1756 	 *  of an escape sequence.
1757 	 */
1758 	if (vc->vc_state == ESosc && c>=8 && c<=13) /* ... except for OSC */
1759 		return;
1760 	switch (c) {
1761 	case 0:
1762 		return;
1763 	case 7:
1764 		if (vc->vc_state == ESosc)
1765 			vc->vc_state = ESnormal;
1766 		else if (vc->vc_bell_duration)
1767 			kd_mksound(vc->vc_bell_pitch, vc->vc_bell_duration);
1768 		return;
1769 	case 8:
1770 		bs(vc);
1771 		return;
1772 	case 9:
1773 		vc->vc_pos -= (vc->vc_x << 1);
1774 		while (vc->vc_x < vc->vc_cols - 1) {
1775 			vc->vc_x++;
1776 			if (vc->vc_tab_stop[7 & (vc->vc_x >> 5)] & (1 << (vc->vc_x & 31)))
1777 				break;
1778 		}
1779 		vc->vc_pos += (vc->vc_x << 1);
1780 		notify_write(vc, '\t');
1781 		return;
1782 	case 10: case 11: case 12:
1783 		lf(vc);
1784 		if (!is_kbd(vc, lnm))
1785 			return;
1786 	case 13:
1787 		cr(vc);
1788 		return;
1789 	case 14:
1790 		vc->vc_charset = 1;
1791 		vc->vc_translate = set_translate(vc->vc_G1_charset, vc);
1792 		vc->vc_disp_ctrl = 1;
1793 		return;
1794 	case 15:
1795 		vc->vc_charset = 0;
1796 		vc->vc_translate = set_translate(vc->vc_G0_charset, vc);
1797 		vc->vc_disp_ctrl = 0;
1798 		return;
1799 	case 24: case 26:
1800 		vc->vc_state = ESnormal;
1801 		return;
1802 	case 27:
1803 		vc->vc_state = ESesc;
1804 		return;
1805 	case 127:
1806 		del(vc);
1807 		return;
1808 	case 128+27:
1809 		vc->vc_state = ESsquare;
1810 		return;
1811 	}
1812 	switch(vc->vc_state) {
1813 	case ESesc:
1814 		vc->vc_state = ESnormal;
1815 		switch (c) {
1816 		case '[':
1817 			vc->vc_state = ESsquare;
1818 			return;
1819 		case ']':
1820 			vc->vc_state = ESnonstd;
1821 			return;
1822 		case '%':
1823 			vc->vc_state = ESpercent;
1824 			return;
1825 		case 'E':
1826 			cr(vc);
1827 			lf(vc);
1828 			return;
1829 		case 'M':
1830 			ri(vc);
1831 			return;
1832 		case 'D':
1833 			lf(vc);
1834 			return;
1835 		case 'H':
1836 			vc->vc_tab_stop[7 & (vc->vc_x >> 5)] |= (1 << (vc->vc_x & 31));
1837 			return;
1838 		case 'Z':
1839 			respond_ID(tty);
1840 			return;
1841 		case '7':
1842 			save_cur(vc);
1843 			return;
1844 		case '8':
1845 			restore_cur(vc);
1846 			return;
1847 		case '(':
1848 			vc->vc_state = ESsetG0;
1849 			return;
1850 		case ')':
1851 			vc->vc_state = ESsetG1;
1852 			return;
1853 		case '#':
1854 			vc->vc_state = EShash;
1855 			return;
1856 		case 'c':
1857 			reset_terminal(vc, 1);
1858 			return;
1859 		case '>':  /* Numeric keypad */
1860 			clr_kbd(vc, kbdapplic);
1861 			return;
1862 		case '=':  /* Appl. keypad */
1863 			set_kbd(vc, kbdapplic);
1864 			return;
1865 		}
1866 		return;
1867 	case ESnonstd:
1868 		if (c=='P') {   /* palette escape sequence */
1869 			for (vc->vc_npar = 0; vc->vc_npar < NPAR; vc->vc_npar++)
1870 				vc->vc_par[vc->vc_npar] = 0;
1871 			vc->vc_npar = 0;
1872 			vc->vc_state = ESpalette;
1873 			return;
1874 		} else if (c=='R') {   /* reset palette */
1875 			reset_palette(vc);
1876 			vc->vc_state = ESnormal;
1877 		} else if (c>='0' && c<='9')
1878 			vc->vc_state = ESosc;
1879 		else
1880 			vc->vc_state = ESnormal;
1881 		return;
1882 	case ESpalette:
1883 		if (isxdigit(c)) {
1884 			vc->vc_par[vc->vc_npar++] = hex_to_bin(c);
1885 			if (vc->vc_npar == 7) {
1886 				int i = vc->vc_par[0] * 3, j = 1;
1887 				vc->vc_palette[i] = 16 * vc->vc_par[j++];
1888 				vc->vc_palette[i++] += vc->vc_par[j++];
1889 				vc->vc_palette[i] = 16 * vc->vc_par[j++];
1890 				vc->vc_palette[i++] += vc->vc_par[j++];
1891 				vc->vc_palette[i] = 16 * vc->vc_par[j++];
1892 				vc->vc_palette[i] += vc->vc_par[j];
1893 				set_palette(vc);
1894 				vc->vc_state = ESnormal;
1895 			}
1896 		} else
1897 			vc->vc_state = ESnormal;
1898 		return;
1899 	case ESsquare:
1900 		for (vc->vc_npar = 0; vc->vc_npar < NPAR; vc->vc_npar++)
1901 			vc->vc_par[vc->vc_npar] = 0;
1902 		vc->vc_npar = 0;
1903 		vc->vc_state = ESgetpars;
1904 		if (c == '[') { /* Function key */
1905 			vc->vc_state=ESfunckey;
1906 			return;
1907 		}
1908 		vc->vc_ques = (c == '?');
1909 		if (vc->vc_ques)
1910 			return;
1911 	case ESgetpars:
1912 		if (c == ';' && vc->vc_npar < NPAR - 1) {
1913 			vc->vc_npar++;
1914 			return;
1915 		} else if (c>='0' && c<='9') {
1916 			vc->vc_par[vc->vc_npar] *= 10;
1917 			vc->vc_par[vc->vc_npar] += c - '0';
1918 			return;
1919 		}
1920 		vc->vc_state = ESnormal;
1921 		switch(c) {
1922 		case 'h':
1923 			set_mode(vc, 1);
1924 			return;
1925 		case 'l':
1926 			set_mode(vc, 0);
1927 			return;
1928 		case 'c':
1929 			if (vc->vc_ques) {
1930 				if (vc->vc_par[0])
1931 					vc->vc_cursor_type = vc->vc_par[0] | (vc->vc_par[1] << 8) | (vc->vc_par[2] << 16);
1932 				else
1933 					vc->vc_cursor_type = cur_default;
1934 				return;
1935 			}
1936 			break;
1937 		case 'm':
1938 			if (vc->vc_ques) {
1939 				clear_selection();
1940 				if (vc->vc_par[0])
1941 					vc->vc_complement_mask = vc->vc_par[0] << 8 | vc->vc_par[1];
1942 				else
1943 					vc->vc_complement_mask = vc->vc_s_complement_mask;
1944 				return;
1945 			}
1946 			break;
1947 		case 'n':
1948 			if (!vc->vc_ques) {
1949 				if (vc->vc_par[0] == 5)
1950 					status_report(tty);
1951 				else if (vc->vc_par[0] == 6)
1952 					cursor_report(vc, tty);
1953 			}
1954 			return;
1955 		}
1956 		if (vc->vc_ques) {
1957 			vc->vc_ques = 0;
1958 			return;
1959 		}
1960 		switch(c) {
1961 		case 'G': case '`':
1962 			if (vc->vc_par[0])
1963 				vc->vc_par[0]--;
1964 			gotoxy(vc, vc->vc_par[0], vc->vc_y);
1965 			return;
1966 		case 'A':
1967 			if (!vc->vc_par[0])
1968 				vc->vc_par[0]++;
1969 			gotoxy(vc, vc->vc_x, vc->vc_y - vc->vc_par[0]);
1970 			return;
1971 		case 'B': case 'e':
1972 			if (!vc->vc_par[0])
1973 				vc->vc_par[0]++;
1974 			gotoxy(vc, vc->vc_x, vc->vc_y + vc->vc_par[0]);
1975 			return;
1976 		case 'C': case 'a':
1977 			if (!vc->vc_par[0])
1978 				vc->vc_par[0]++;
1979 			gotoxy(vc, vc->vc_x + vc->vc_par[0], vc->vc_y);
1980 			return;
1981 		case 'D':
1982 			if (!vc->vc_par[0])
1983 				vc->vc_par[0]++;
1984 			gotoxy(vc, vc->vc_x - vc->vc_par[0], vc->vc_y);
1985 			return;
1986 		case 'E':
1987 			if (!vc->vc_par[0])
1988 				vc->vc_par[0]++;
1989 			gotoxy(vc, 0, vc->vc_y + vc->vc_par[0]);
1990 			return;
1991 		case 'F':
1992 			if (!vc->vc_par[0])
1993 				vc->vc_par[0]++;
1994 			gotoxy(vc, 0, vc->vc_y - vc->vc_par[0]);
1995 			return;
1996 		case 'd':
1997 			if (vc->vc_par[0])
1998 				vc->vc_par[0]--;
1999 			gotoxay(vc, vc->vc_x ,vc->vc_par[0]);
2000 			return;
2001 		case 'H': case 'f':
2002 			if (vc->vc_par[0])
2003 				vc->vc_par[0]--;
2004 			if (vc->vc_par[1])
2005 				vc->vc_par[1]--;
2006 			gotoxay(vc, vc->vc_par[1], vc->vc_par[0]);
2007 			return;
2008 		case 'J':
2009 			csi_J(vc, vc->vc_par[0]);
2010 			return;
2011 		case 'K':
2012 			csi_K(vc, vc->vc_par[0]);
2013 			return;
2014 		case 'L':
2015 			csi_L(vc, vc->vc_par[0]);
2016 			return;
2017 		case 'M':
2018 			csi_M(vc, vc->vc_par[0]);
2019 			return;
2020 		case 'P':
2021 			csi_P(vc, vc->vc_par[0]);
2022 			return;
2023 		case 'c':
2024 			if (!vc->vc_par[0])
2025 				respond_ID(tty);
2026 			return;
2027 		case 'g':
2028 			if (!vc->vc_par[0])
2029 				vc->vc_tab_stop[7 & (vc->vc_x >> 5)] &= ~(1 << (vc->vc_x & 31));
2030 			else if (vc->vc_par[0] == 3) {
2031 				vc->vc_tab_stop[0] =
2032 					vc->vc_tab_stop[1] =
2033 					vc->vc_tab_stop[2] =
2034 					vc->vc_tab_stop[3] =
2035 					vc->vc_tab_stop[4] =
2036 					vc->vc_tab_stop[5] =
2037 					vc->vc_tab_stop[6] =
2038 					vc->vc_tab_stop[7] = 0;
2039 			}
2040 			return;
2041 		case 'm':
2042 			csi_m(vc);
2043 			return;
2044 		case 'q': /* DECLL - but only 3 leds */
2045 			/* map 0,1,2,3 to 0,1,2,4 */
2046 			if (vc->vc_par[0] < 4)
2047 				vt_set_led_state(vc->vc_num,
2048 					    (vc->vc_par[0] < 3) ? vc->vc_par[0] : 4);
2049 			return;
2050 		case 'r':
2051 			if (!vc->vc_par[0])
2052 				vc->vc_par[0]++;
2053 			if (!vc->vc_par[1])
2054 				vc->vc_par[1] = vc->vc_rows;
2055 			/* Minimum allowed region is 2 lines */
2056 			if (vc->vc_par[0] < vc->vc_par[1] &&
2057 			    vc->vc_par[1] <= vc->vc_rows) {
2058 				vc->vc_top = vc->vc_par[0] - 1;
2059 				vc->vc_bottom = vc->vc_par[1];
2060 				gotoxay(vc, 0, 0);
2061 			}
2062 			return;
2063 		case 's':
2064 			save_cur(vc);
2065 			return;
2066 		case 'u':
2067 			restore_cur(vc);
2068 			return;
2069 		case 'X':
2070 			csi_X(vc, vc->vc_par[0]);
2071 			return;
2072 		case '@':
2073 			csi_at(vc, vc->vc_par[0]);
2074 			return;
2075 		case ']': /* setterm functions */
2076 			setterm_command(vc);
2077 			return;
2078 		}
2079 		return;
2080 	case ESpercent:
2081 		vc->vc_state = ESnormal;
2082 		switch (c) {
2083 		case '@':  /* defined in ISO 2022 */
2084 			vc->vc_utf = 0;
2085 			return;
2086 		case 'G':  /* prelim official escape code */
2087 		case '8':  /* retained for compatibility */
2088 			vc->vc_utf = 1;
2089 			return;
2090 		}
2091 		return;
2092 	case ESfunckey:
2093 		vc->vc_state = ESnormal;
2094 		return;
2095 	case EShash:
2096 		vc->vc_state = ESnormal;
2097 		if (c == '8') {
2098 			/* DEC screen alignment test. kludge :-) */
2099 			vc->vc_video_erase_char =
2100 				(vc->vc_video_erase_char & 0xff00) | 'E';
2101 			csi_J(vc, 2);
2102 			vc->vc_video_erase_char =
2103 				(vc->vc_video_erase_char & 0xff00) | ' ';
2104 			do_update_region(vc, vc->vc_origin, vc->vc_screenbuf_size / 2);
2105 		}
2106 		return;
2107 	case ESsetG0:
2108 		if (c == '0')
2109 			vc->vc_G0_charset = GRAF_MAP;
2110 		else if (c == 'B')
2111 			vc->vc_G0_charset = LAT1_MAP;
2112 		else if (c == 'U')
2113 			vc->vc_G0_charset = IBMPC_MAP;
2114 		else if (c == 'K')
2115 			vc->vc_G0_charset = USER_MAP;
2116 		if (vc->vc_charset == 0)
2117 			vc->vc_translate = set_translate(vc->vc_G0_charset, vc);
2118 		vc->vc_state = ESnormal;
2119 		return;
2120 	case ESsetG1:
2121 		if (c == '0')
2122 			vc->vc_G1_charset = GRAF_MAP;
2123 		else if (c == 'B')
2124 			vc->vc_G1_charset = LAT1_MAP;
2125 		else if (c == 'U')
2126 			vc->vc_G1_charset = IBMPC_MAP;
2127 		else if (c == 'K')
2128 			vc->vc_G1_charset = USER_MAP;
2129 		if (vc->vc_charset == 1)
2130 			vc->vc_translate = set_translate(vc->vc_G1_charset, vc);
2131 		vc->vc_state = ESnormal;
2132 		return;
2133 	case ESosc:
2134 		return;
2135 	default:
2136 		vc->vc_state = ESnormal;
2137 	}
2138 }
2139 
2140 /* is_double_width() is based on the wcwidth() implementation by
2141  * Markus Kuhn -- 2007-05-26 (Unicode 5.0)
2142  * Latest version: http://www.cl.cam.ac.uk/~mgk25/ucs/wcwidth.c
2143  */
2144 struct interval {
2145 	uint32_t first;
2146 	uint32_t last;
2147 };
2148 
2149 static int ucs_cmp(const void *key, const void *elt)
2150 {
2151 	uint32_t ucs = *(uint32_t *)key;
2152 	struct interval e = *(struct interval *) elt;
2153 
2154 	if (ucs > e.last)
2155 		return 1;
2156 	else if (ucs < e.first)
2157 		return -1;
2158 	return 0;
2159 }
2160 
2161 static int is_double_width(uint32_t ucs)
2162 {
2163 	static const struct interval double_width[] = {
2164 		{ 0x1100, 0x115F }, { 0x2329, 0x232A }, { 0x2E80, 0x303E },
2165 		{ 0x3040, 0xA4CF }, { 0xAC00, 0xD7A3 }, { 0xF900, 0xFAFF },
2166 		{ 0xFE10, 0xFE19 }, { 0xFE30, 0xFE6F }, { 0xFF00, 0xFF60 },
2167 		{ 0xFFE0, 0xFFE6 }, { 0x20000, 0x2FFFD }, { 0x30000, 0x3FFFD }
2168 	};
2169 	if (ucs < double_width[0].first ||
2170 	    ucs > double_width[ARRAY_SIZE(double_width) - 1].last)
2171 		return 0;
2172 
2173 	return bsearch(&ucs, double_width, ARRAY_SIZE(double_width),
2174 			sizeof(struct interval), ucs_cmp) != NULL;
2175 }
2176 
2177 static void con_flush(struct vc_data *vc, unsigned long draw_from,
2178 		unsigned long draw_to, int *draw_x)
2179 {
2180 	if (*draw_x < 0)
2181 		return;
2182 
2183 	vc->vc_sw->con_putcs(vc, (u16 *)draw_from,
2184 			(u16 *)draw_to - (u16 *)draw_from, vc->vc_y, *draw_x);
2185 	*draw_x = -1;
2186 }
2187 
2188 /* acquires console_lock */
2189 static int do_con_write(struct tty_struct *tty, const unsigned char *buf, int count)
2190 {
2191 	int c, tc, ok, n = 0, draw_x = -1;
2192 	unsigned int currcons;
2193 	unsigned long draw_from = 0, draw_to = 0;
2194 	struct vc_data *vc;
2195 	unsigned char vc_attr;
2196 	struct vt_notifier_param param;
2197 	uint8_t rescan;
2198 	uint8_t inverse;
2199 	uint8_t width;
2200 	u16 himask, charmask;
2201 
2202 	if (in_interrupt())
2203 		return count;
2204 
2205 	might_sleep();
2206 
2207 	console_lock();
2208 	vc = tty->driver_data;
2209 	if (vc == NULL) {
2210 		pr_err("vt: argh, driver_data is NULL !\n");
2211 		console_unlock();
2212 		return 0;
2213 	}
2214 
2215 	currcons = vc->vc_num;
2216 	if (!vc_cons_allocated(currcons)) {
2217 		/* could this happen? */
2218 		pr_warn_once("con_write: tty %d not allocated\n", currcons+1);
2219 		console_unlock();
2220 		return 0;
2221 	}
2222 
2223 	himask = vc->vc_hi_font_mask;
2224 	charmask = himask ? 0x1ff : 0xff;
2225 
2226 	/* undraw cursor first */
2227 	if (con_is_fg(vc))
2228 		hide_cursor(vc);
2229 
2230 	param.vc = vc;
2231 
2232 	while (!tty->stopped && count) {
2233 		int orig = *buf;
2234 		c = orig;
2235 		buf++;
2236 		n++;
2237 		count--;
2238 		rescan = 0;
2239 		inverse = 0;
2240 		width = 1;
2241 
2242 		/* Do no translation at all in control states */
2243 		if (vc->vc_state != ESnormal) {
2244 			tc = c;
2245 		} else if (vc->vc_utf && !vc->vc_disp_ctrl) {
2246 		    /* Combine UTF-8 into Unicode in vc_utf_char.
2247 		     * vc_utf_count is the number of continuation bytes still
2248 		     * expected to arrive.
2249 		     * vc_npar is the number of continuation bytes arrived so
2250 		     * far
2251 		     */
2252 rescan_last_byte:
2253 		    if ((c & 0xc0) == 0x80) {
2254 			/* Continuation byte received */
2255 			static const uint32_t utf8_length_changes[] = { 0x0000007f, 0x000007ff, 0x0000ffff, 0x001fffff, 0x03ffffff, 0x7fffffff };
2256 			if (vc->vc_utf_count) {
2257 			    vc->vc_utf_char = (vc->vc_utf_char << 6) | (c & 0x3f);
2258 			    vc->vc_npar++;
2259 			    if (--vc->vc_utf_count) {
2260 				/* Still need some bytes */
2261 				continue;
2262 			    }
2263 			    /* Got a whole character */
2264 			    c = vc->vc_utf_char;
2265 			    /* Reject overlong sequences */
2266 			    if (c <= utf8_length_changes[vc->vc_npar - 1] ||
2267 					c > utf8_length_changes[vc->vc_npar])
2268 				c = 0xfffd;
2269 			} else {
2270 			    /* Unexpected continuation byte */
2271 			    vc->vc_utf_count = 0;
2272 			    c = 0xfffd;
2273 			}
2274 		    } else {
2275 			/* Single ASCII byte or first byte of a sequence received */
2276 			if (vc->vc_utf_count) {
2277 			    /* Continuation byte expected */
2278 			    rescan = 1;
2279 			    vc->vc_utf_count = 0;
2280 			    c = 0xfffd;
2281 			} else if (c > 0x7f) {
2282 			    /* First byte of a multibyte sequence received */
2283 			    vc->vc_npar = 0;
2284 			    if ((c & 0xe0) == 0xc0) {
2285 				vc->vc_utf_count = 1;
2286 				vc->vc_utf_char = (c & 0x1f);
2287 			    } else if ((c & 0xf0) == 0xe0) {
2288 				vc->vc_utf_count = 2;
2289 				vc->vc_utf_char = (c & 0x0f);
2290 			    } else if ((c & 0xf8) == 0xf0) {
2291 				vc->vc_utf_count = 3;
2292 				vc->vc_utf_char = (c & 0x07);
2293 			    } else if ((c & 0xfc) == 0xf8) {
2294 				vc->vc_utf_count = 4;
2295 				vc->vc_utf_char = (c & 0x03);
2296 			    } else if ((c & 0xfe) == 0xfc) {
2297 				vc->vc_utf_count = 5;
2298 				vc->vc_utf_char = (c & 0x01);
2299 			    } else {
2300 				/* 254 and 255 are invalid */
2301 				c = 0xfffd;
2302 			    }
2303 			    if (vc->vc_utf_count) {
2304 				/* Still need some bytes */
2305 				continue;
2306 			    }
2307 			}
2308 			/* Nothing to do if an ASCII byte was received */
2309 		    }
2310 		    /* End of UTF-8 decoding. */
2311 		    /* c is the received character, or U+FFFD for invalid sequences. */
2312 		    /* Replace invalid Unicode code points with U+FFFD too */
2313 		    if ((c >= 0xd800 && c <= 0xdfff) || c == 0xfffe || c == 0xffff)
2314 			c = 0xfffd;
2315 		    tc = c;
2316 		} else {	/* no utf or alternate charset mode */
2317 		    tc = vc_translate(vc, c);
2318 		}
2319 
2320 		param.c = tc;
2321 		if (atomic_notifier_call_chain(&vt_notifier_list, VT_PREWRITE,
2322 					&param) == NOTIFY_STOP)
2323 			continue;
2324 
2325                 /* If the original code was a control character we
2326                  * only allow a glyph to be displayed if the code is
2327                  * not normally used (such as for cursor movement) or
2328                  * if the disp_ctrl mode has been explicitly enabled.
2329                  * Certain characters (as given by the CTRL_ALWAYS
2330                  * bitmap) are always displayed as control characters,
2331                  * as the console would be pretty useless without
2332                  * them; to display an arbitrary font position use the
2333                  * direct-to-font zone in UTF-8 mode.
2334                  */
2335                 ok = tc && (c >= 32 ||
2336 			    !(vc->vc_disp_ctrl ? (CTRL_ALWAYS >> c) & 1 :
2337 				  vc->vc_utf || ((CTRL_ACTION >> c) & 1)))
2338 			&& (c != 127 || vc->vc_disp_ctrl)
2339 			&& (c != 128+27);
2340 
2341 		if (vc->vc_state == ESnormal && ok) {
2342 			if (vc->vc_utf && !vc->vc_disp_ctrl) {
2343 				if (is_double_width(c))
2344 					width = 2;
2345 			}
2346 			/* Now try to find out how to display it */
2347 			tc = conv_uni_to_pc(vc, tc);
2348 			if (tc & ~charmask) {
2349 				if (tc == -1 || tc == -2) {
2350 				    continue; /* nothing to display */
2351 				}
2352 				/* Glyph not found */
2353 				if ((!(vc->vc_utf && !vc->vc_disp_ctrl) || c < 128) && !(c & ~charmask)) {
2354 				    /* In legacy mode use the glyph we get by a 1:1 mapping.
2355 				       This would make absolutely no sense with Unicode in mind,
2356 				       but do this for ASCII characters since a font may lack
2357 				       Unicode mapping info and we don't want to end up with
2358 				       having question marks only. */
2359 				    tc = c;
2360 				} else {
2361 				    /* Display U+FFFD. If it's not found, display an inverse question mark. */
2362 				    tc = conv_uni_to_pc(vc, 0xfffd);
2363 				    if (tc < 0) {
2364 					inverse = 1;
2365 					tc = conv_uni_to_pc(vc, '?');
2366 					if (tc < 0) tc = '?';
2367 				    }
2368 				}
2369 			}
2370 
2371 			if (!inverse) {
2372 				vc_attr = vc->vc_attr;
2373 			} else {
2374 				/* invert vc_attr */
2375 				if (!vc->vc_can_do_color) {
2376 					vc_attr = (vc->vc_attr) ^ 0x08;
2377 				} else if (vc->vc_hi_font_mask == 0x100) {
2378 					vc_attr = ((vc->vc_attr) & 0x11) | (((vc->vc_attr) & 0xe0) >> 4) | (((vc->vc_attr) & 0x0e) << 4);
2379 				} else {
2380 					vc_attr = ((vc->vc_attr) & 0x88) | (((vc->vc_attr) & 0x70) >> 4) | (((vc->vc_attr) & 0x07) << 4);
2381 				}
2382 				con_flush(vc, draw_from, draw_to, &draw_x);
2383 			}
2384 
2385 			while (1) {
2386 				if (vc->vc_need_wrap || vc->vc_decim)
2387 					con_flush(vc, draw_from, draw_to,
2388 							&draw_x);
2389 				if (vc->vc_need_wrap) {
2390 					cr(vc);
2391 					lf(vc);
2392 				}
2393 				if (vc->vc_decim)
2394 					insert_char(vc, 1);
2395 				scr_writew(himask ?
2396 					     ((vc_attr << 8) & ~himask) + ((tc & 0x100) ? himask : 0) + (tc & 0xff) :
2397 					     (vc_attr << 8) + tc,
2398 					   (u16 *) vc->vc_pos);
2399 				if (con_should_update(vc) && draw_x < 0) {
2400 					draw_x = vc->vc_x;
2401 					draw_from = vc->vc_pos;
2402 				}
2403 				if (vc->vc_x == vc->vc_cols - 1) {
2404 					vc->vc_need_wrap = vc->vc_decawm;
2405 					draw_to = vc->vc_pos + 2;
2406 				} else {
2407 					vc->vc_x++;
2408 					draw_to = (vc->vc_pos += 2);
2409 				}
2410 
2411 				if (!--width) break;
2412 
2413 				tc = conv_uni_to_pc(vc, ' '); /* A space is printed in the second column */
2414 				if (tc < 0) tc = ' ';
2415 			}
2416 			notify_write(vc, c);
2417 
2418 			if (inverse)
2419 				con_flush(vc, draw_from, draw_to, &draw_x);
2420 
2421 			if (rescan) {
2422 				rescan = 0;
2423 				inverse = 0;
2424 				width = 1;
2425 				c = orig;
2426 				goto rescan_last_byte;
2427 			}
2428 			continue;
2429 		}
2430 		con_flush(vc, draw_from, draw_to, &draw_x);
2431 		do_con_trol(tty, vc, orig);
2432 	}
2433 	con_flush(vc, draw_from, draw_to, &draw_x);
2434 	console_conditional_schedule();
2435 	console_unlock();
2436 	notify_update(vc);
2437 	return n;
2438 }
2439 
2440 /*
2441  * This is the console switching callback.
2442  *
2443  * Doing console switching in a process context allows
2444  * us to do the switches asynchronously (needed when we want
2445  * to switch due to a keyboard interrupt).  Synchronization
2446  * with other console code and prevention of re-entrancy is
2447  * ensured with console_lock.
2448  */
2449 static void console_callback(struct work_struct *ignored)
2450 {
2451 	console_lock();
2452 
2453 	if (want_console >= 0) {
2454 		if (want_console != fg_console &&
2455 		    vc_cons_allocated(want_console)) {
2456 			hide_cursor(vc_cons[fg_console].d);
2457 			change_console(vc_cons[want_console].d);
2458 			/* we only changed when the console had already
2459 			   been allocated - a new console is not created
2460 			   in an interrupt routine */
2461 		}
2462 		want_console = -1;
2463 	}
2464 	if (do_poke_blanked_console) { /* do not unblank for a LED change */
2465 		do_poke_blanked_console = 0;
2466 		poke_blanked_console();
2467 	}
2468 	if (scrollback_delta) {
2469 		struct vc_data *vc = vc_cons[fg_console].d;
2470 		clear_selection();
2471 		if (vc->vc_mode == KD_TEXT && vc->vc_sw->con_scrolldelta)
2472 			vc->vc_sw->con_scrolldelta(vc, scrollback_delta);
2473 		scrollback_delta = 0;
2474 	}
2475 	if (blank_timer_expired) {
2476 		do_blank_screen(0);
2477 		blank_timer_expired = 0;
2478 	}
2479 	notify_update(vc_cons[fg_console].d);
2480 
2481 	console_unlock();
2482 }
2483 
2484 int set_console(int nr)
2485 {
2486 	struct vc_data *vc = vc_cons[fg_console].d;
2487 
2488 	if (!vc_cons_allocated(nr) || vt_dont_switch ||
2489 		(vc->vt_mode.mode == VT_AUTO && vc->vc_mode == KD_GRAPHICS)) {
2490 
2491 		/*
2492 		 * Console switch will fail in console_callback() or
2493 		 * change_console() so there is no point scheduling
2494 		 * the callback
2495 		 *
2496 		 * Existing set_console() users don't check the return
2497 		 * value so this shouldn't break anything
2498 		 */
2499 		return -EINVAL;
2500 	}
2501 
2502 	want_console = nr;
2503 	schedule_console_callback();
2504 
2505 	return 0;
2506 }
2507 
2508 struct tty_driver *console_driver;
2509 
2510 #ifdef CONFIG_VT_CONSOLE
2511 
2512 /**
2513  * vt_kmsg_redirect() - Sets/gets the kernel message console
2514  * @new:	The new virtual terminal number or -1 if the console should stay
2515  * 		unchanged
2516  *
2517  * By default, the kernel messages are always printed on the current virtual
2518  * console. However, the user may modify that default with the
2519  * TIOCL_SETKMSGREDIRECT ioctl call.
2520  *
2521  * This function sets the kernel message console to be @new. It returns the old
2522  * virtual console number. The virtual terminal number 0 (both as parameter and
2523  * return value) means no redirection (i.e. always printed on the currently
2524  * active console).
2525  *
2526  * The parameter -1 means that only the current console is returned, but the
2527  * value is not modified. You may use the macro vt_get_kmsg_redirect() in that
2528  * case to make the code more understandable.
2529  *
2530  * When the kernel is compiled without CONFIG_VT_CONSOLE, this function ignores
2531  * the parameter and always returns 0.
2532  */
2533 int vt_kmsg_redirect(int new)
2534 {
2535 	static int kmsg_con;
2536 
2537 	if (new != -1)
2538 		return xchg(&kmsg_con, new);
2539 	else
2540 		return kmsg_con;
2541 }
2542 
2543 /*
2544  *	Console on virtual terminal
2545  *
2546  * The console must be locked when we get here.
2547  */
2548 
2549 static void vt_console_print(struct console *co, const char *b, unsigned count)
2550 {
2551 	struct vc_data *vc = vc_cons[fg_console].d;
2552 	unsigned char c;
2553 	static DEFINE_SPINLOCK(printing_lock);
2554 	const ushort *start;
2555 	ushort cnt = 0;
2556 	ushort myx;
2557 	int kmsg_console;
2558 
2559 	/* console busy or not yet initialized */
2560 	if (!printable)
2561 		return;
2562 	if (!spin_trylock(&printing_lock))
2563 		return;
2564 
2565 	kmsg_console = vt_get_kmsg_redirect();
2566 	if (kmsg_console && vc_cons_allocated(kmsg_console - 1))
2567 		vc = vc_cons[kmsg_console - 1].d;
2568 
2569 	/* read `x' only after setting currcons properly (otherwise
2570 	   the `x' macro will read the x of the foreground console). */
2571 	myx = vc->vc_x;
2572 
2573 	if (!vc_cons_allocated(fg_console)) {
2574 		/* impossible */
2575 		/* printk("vt_console_print: tty %d not allocated ??\n", currcons+1); */
2576 		goto quit;
2577 	}
2578 
2579 	if (vc->vc_mode != KD_TEXT && !vt_force_oops_output(vc))
2580 		goto quit;
2581 
2582 	/* undraw cursor first */
2583 	if (con_is_fg(vc))
2584 		hide_cursor(vc);
2585 
2586 	start = (ushort *)vc->vc_pos;
2587 
2588 	/* Contrived structure to try to emulate original need_wrap behaviour
2589 	 * Problems caused when we have need_wrap set on '\n' character */
2590 	while (count--) {
2591 		c = *b++;
2592 		if (c == 10 || c == 13 || c == 8 || vc->vc_need_wrap) {
2593 			if (cnt > 0) {
2594 				if (con_is_visible(vc))
2595 					vc->vc_sw->con_putcs(vc, start, cnt, vc->vc_y, vc->vc_x);
2596 				vc->vc_x += cnt;
2597 				if (vc->vc_need_wrap)
2598 					vc->vc_x--;
2599 				cnt = 0;
2600 			}
2601 			if (c == 8) {		/* backspace */
2602 				bs(vc);
2603 				start = (ushort *)vc->vc_pos;
2604 				myx = vc->vc_x;
2605 				continue;
2606 			}
2607 			if (c != 13)
2608 				lf(vc);
2609 			cr(vc);
2610 			start = (ushort *)vc->vc_pos;
2611 			myx = vc->vc_x;
2612 			if (c == 10 || c == 13)
2613 				continue;
2614 		}
2615 		scr_writew((vc->vc_attr << 8) + c, (unsigned short *)vc->vc_pos);
2616 		notify_write(vc, c);
2617 		cnt++;
2618 		if (myx == vc->vc_cols - 1) {
2619 			vc->vc_need_wrap = 1;
2620 			continue;
2621 		}
2622 		vc->vc_pos += 2;
2623 		myx++;
2624 	}
2625 	if (cnt > 0) {
2626 		if (con_is_visible(vc))
2627 			vc->vc_sw->con_putcs(vc, start, cnt, vc->vc_y, vc->vc_x);
2628 		vc->vc_x += cnt;
2629 		if (vc->vc_x == vc->vc_cols) {
2630 			vc->vc_x--;
2631 			vc->vc_need_wrap = 1;
2632 		}
2633 	}
2634 	set_cursor(vc);
2635 	notify_update(vc);
2636 
2637 quit:
2638 	spin_unlock(&printing_lock);
2639 }
2640 
2641 static struct tty_driver *vt_console_device(struct console *c, int *index)
2642 {
2643 	*index = c->index ? c->index-1 : fg_console;
2644 	return console_driver;
2645 }
2646 
2647 static struct console vt_console_driver = {
2648 	.name		= "tty",
2649 	.write		= vt_console_print,
2650 	.device		= vt_console_device,
2651 	.unblank	= unblank_screen,
2652 	.flags		= CON_PRINTBUFFER,
2653 	.index		= -1,
2654 };
2655 #endif
2656 
2657 /*
2658  *	Handling of Linux-specific VC ioctls
2659  */
2660 
2661 /*
2662  * Generally a bit racy with respect to console_lock();.
2663  *
2664  * There are some functions which don't need it.
2665  *
2666  * There are some functions which can sleep for arbitrary periods
2667  * (paste_selection) but we don't need the lock there anyway.
2668  *
2669  * set_selection has locking, and definitely needs it
2670  */
2671 
2672 int tioclinux(struct tty_struct *tty, unsigned long arg)
2673 {
2674 	char type, data;
2675 	char __user *p = (char __user *)arg;
2676 	int lines;
2677 	int ret;
2678 
2679 	if (current->signal->tty != tty && !capable(CAP_SYS_ADMIN))
2680 		return -EPERM;
2681 	if (get_user(type, p))
2682 		return -EFAULT;
2683 	ret = 0;
2684 
2685 	switch (type)
2686 	{
2687 		case TIOCL_SETSEL:
2688 			console_lock();
2689 			ret = set_selection((struct tiocl_selection __user *)(p+1), tty);
2690 			console_unlock();
2691 			break;
2692 		case TIOCL_PASTESEL:
2693 			ret = paste_selection(tty);
2694 			break;
2695 		case TIOCL_UNBLANKSCREEN:
2696 			console_lock();
2697 			unblank_screen();
2698 			console_unlock();
2699 			break;
2700 		case TIOCL_SELLOADLUT:
2701 			console_lock();
2702 			ret = sel_loadlut(p);
2703 			console_unlock();
2704 			break;
2705 		case TIOCL_GETSHIFTSTATE:
2706 
2707 	/*
2708 	 * Make it possible to react to Shift+Mousebutton.
2709 	 * Note that 'shift_state' is an undocumented
2710 	 * kernel-internal variable; programs not closely
2711 	 * related to the kernel should not use this.
2712 	 */
2713 			data = vt_get_shift_state();
2714 			ret = put_user(data, p);
2715 			break;
2716 		case TIOCL_GETMOUSEREPORTING:
2717 			console_lock();	/* May be overkill */
2718 			data = mouse_reporting();
2719 			console_unlock();
2720 			ret = put_user(data, p);
2721 			break;
2722 		case TIOCL_SETVESABLANK:
2723 			console_lock();
2724 			ret = set_vesa_blanking(p);
2725 			console_unlock();
2726 			break;
2727 		case TIOCL_GETKMSGREDIRECT:
2728 			data = vt_get_kmsg_redirect();
2729 			ret = put_user(data, p);
2730 			break;
2731 		case TIOCL_SETKMSGREDIRECT:
2732 			if (!capable(CAP_SYS_ADMIN)) {
2733 				ret = -EPERM;
2734 			} else {
2735 				if (get_user(data, p+1))
2736 					ret = -EFAULT;
2737 				else
2738 					vt_kmsg_redirect(data);
2739 			}
2740 			break;
2741 		case TIOCL_GETFGCONSOLE:
2742 			/* No locking needed as this is a transiently
2743 			   correct return anyway if the caller hasn't
2744 			   disabled switching */
2745 			ret = fg_console;
2746 			break;
2747 		case TIOCL_SCROLLCONSOLE:
2748 			if (get_user(lines, (s32 __user *)(p+4))) {
2749 				ret = -EFAULT;
2750 			} else {
2751 				/* Need the console lock here. Note that lots
2752 				   of other calls need fixing before the lock
2753 				   is actually useful ! */
2754 				console_lock();
2755 				scrollfront(vc_cons[fg_console].d, lines);
2756 				console_unlock();
2757 				ret = 0;
2758 			}
2759 			break;
2760 		case TIOCL_BLANKSCREEN:	/* until explicitly unblanked, not only poked */
2761 			console_lock();
2762 			ignore_poke = 1;
2763 			do_blank_screen(0);
2764 			console_unlock();
2765 			break;
2766 		case TIOCL_BLANKEDSCREEN:
2767 			ret = console_blanked;
2768 			break;
2769 		default:
2770 			ret = -EINVAL;
2771 			break;
2772 	}
2773 	return ret;
2774 }
2775 
2776 /*
2777  * /dev/ttyN handling
2778  */
2779 
2780 static int con_write(struct tty_struct *tty, const unsigned char *buf, int count)
2781 {
2782 	int	retval;
2783 
2784 	retval = do_con_write(tty, buf, count);
2785 	con_flush_chars(tty);
2786 
2787 	return retval;
2788 }
2789 
2790 static int con_put_char(struct tty_struct *tty, unsigned char ch)
2791 {
2792 	if (in_interrupt())
2793 		return 0;	/* n_r3964 calls put_char() from interrupt context */
2794 	return do_con_write(tty, &ch, 1);
2795 }
2796 
2797 static int con_write_room(struct tty_struct *tty)
2798 {
2799 	if (tty->stopped)
2800 		return 0;
2801 	return 32768;		/* No limit, really; we're not buffering */
2802 }
2803 
2804 static int con_chars_in_buffer(struct tty_struct *tty)
2805 {
2806 	return 0;		/* we're not buffering */
2807 }
2808 
2809 /*
2810  * con_throttle and con_unthrottle are only used for
2811  * paste_selection(), which has to stuff in a large number of
2812  * characters...
2813  */
2814 static void con_throttle(struct tty_struct *tty)
2815 {
2816 }
2817 
2818 static void con_unthrottle(struct tty_struct *tty)
2819 {
2820 	struct vc_data *vc = tty->driver_data;
2821 
2822 	wake_up_interruptible(&vc->paste_wait);
2823 }
2824 
2825 /*
2826  * Turn the Scroll-Lock LED on when the tty is stopped
2827  */
2828 static void con_stop(struct tty_struct *tty)
2829 {
2830 	int console_num;
2831 	if (!tty)
2832 		return;
2833 	console_num = tty->index;
2834 	if (!vc_cons_allocated(console_num))
2835 		return;
2836 	vt_kbd_con_stop(console_num);
2837 }
2838 
2839 /*
2840  * Turn the Scroll-Lock LED off when the console is started
2841  */
2842 static void con_start(struct tty_struct *tty)
2843 {
2844 	int console_num;
2845 	if (!tty)
2846 		return;
2847 	console_num = tty->index;
2848 	if (!vc_cons_allocated(console_num))
2849 		return;
2850 	vt_kbd_con_start(console_num);
2851 }
2852 
2853 static void con_flush_chars(struct tty_struct *tty)
2854 {
2855 	struct vc_data *vc;
2856 
2857 	if (in_interrupt())	/* from flush_to_ldisc */
2858 		return;
2859 
2860 	/* if we race with con_close(), vt may be null */
2861 	console_lock();
2862 	vc = tty->driver_data;
2863 	if (vc)
2864 		set_cursor(vc);
2865 	console_unlock();
2866 }
2867 
2868 /*
2869  * Allocate the console screen memory.
2870  */
2871 static int con_install(struct tty_driver *driver, struct tty_struct *tty)
2872 {
2873 	unsigned int currcons = tty->index;
2874 	struct vc_data *vc;
2875 	int ret;
2876 
2877 	console_lock();
2878 	ret = vc_allocate(currcons);
2879 	if (ret)
2880 		goto unlock;
2881 
2882 	vc = vc_cons[currcons].d;
2883 
2884 	/* Still being freed */
2885 	if (vc->port.tty) {
2886 		ret = -ERESTARTSYS;
2887 		goto unlock;
2888 	}
2889 
2890 	ret = tty_port_install(&vc->port, driver, tty);
2891 	if (ret)
2892 		goto unlock;
2893 
2894 	tty->driver_data = vc;
2895 	vc->port.tty = tty;
2896 
2897 	if (!tty->winsize.ws_row && !tty->winsize.ws_col) {
2898 		tty->winsize.ws_row = vc_cons[currcons].d->vc_rows;
2899 		tty->winsize.ws_col = vc_cons[currcons].d->vc_cols;
2900 	}
2901 	if (vc->vc_utf)
2902 		tty->termios.c_iflag |= IUTF8;
2903 	else
2904 		tty->termios.c_iflag &= ~IUTF8;
2905 unlock:
2906 	console_unlock();
2907 	return ret;
2908 }
2909 
2910 static int con_open(struct tty_struct *tty, struct file *filp)
2911 {
2912 	/* everything done in install */
2913 	return 0;
2914 }
2915 
2916 
2917 static void con_close(struct tty_struct *tty, struct file *filp)
2918 {
2919 	/* Nothing to do - we defer to shutdown */
2920 }
2921 
2922 static void con_shutdown(struct tty_struct *tty)
2923 {
2924 	struct vc_data *vc = tty->driver_data;
2925 	BUG_ON(vc == NULL);
2926 	console_lock();
2927 	vc->port.tty = NULL;
2928 	console_unlock();
2929 }
2930 
2931 static int default_color           = 7; /* white */
2932 static int default_italic_color    = 2; // green (ASCII)
2933 static int default_underline_color = 3; // cyan (ASCII)
2934 module_param_named(color, default_color, int, S_IRUGO | S_IWUSR);
2935 module_param_named(italic, default_italic_color, int, S_IRUGO | S_IWUSR);
2936 module_param_named(underline, default_underline_color, int, S_IRUGO | S_IWUSR);
2937 
2938 static void vc_init(struct vc_data *vc, unsigned int rows,
2939 		    unsigned int cols, int do_clear)
2940 {
2941 	int j, k ;
2942 
2943 	vc->vc_cols = cols;
2944 	vc->vc_rows = rows;
2945 	vc->vc_size_row = cols << 1;
2946 	vc->vc_screenbuf_size = vc->vc_rows * vc->vc_size_row;
2947 
2948 	set_origin(vc);
2949 	vc->vc_pos = vc->vc_origin;
2950 	reset_vc(vc);
2951 	for (j=k=0; j<16; j++) {
2952 		vc->vc_palette[k++] = default_red[j] ;
2953 		vc->vc_palette[k++] = default_grn[j] ;
2954 		vc->vc_palette[k++] = default_blu[j] ;
2955 	}
2956 	vc->vc_def_color       = default_color;
2957 	vc->vc_ulcolor         = default_underline_color;
2958 	vc->vc_itcolor         = default_italic_color;
2959 	vc->vc_halfcolor       = 0x08;   /* grey */
2960 	init_waitqueue_head(&vc->paste_wait);
2961 	reset_terminal(vc, do_clear);
2962 }
2963 
2964 /*
2965  * This routine initializes console interrupts, and does nothing
2966  * else. If you want the screen to clear, call tty_write with
2967  * the appropriate escape-sequence.
2968  */
2969 
2970 static int __init con_init(void)
2971 {
2972 	const char *display_desc = NULL;
2973 	struct vc_data *vc;
2974 	unsigned int currcons = 0, i;
2975 
2976 	console_lock();
2977 
2978 	if (conswitchp)
2979 		display_desc = conswitchp->con_startup();
2980 	if (!display_desc) {
2981 		fg_console = 0;
2982 		console_unlock();
2983 		return 0;
2984 	}
2985 
2986 	for (i = 0; i < MAX_NR_CON_DRIVER; i++) {
2987 		struct con_driver *con_driver = &registered_con_driver[i];
2988 
2989 		if (con_driver->con == NULL) {
2990 			con_driver->con = conswitchp;
2991 			con_driver->desc = display_desc;
2992 			con_driver->flag = CON_DRIVER_FLAG_INIT;
2993 			con_driver->first = 0;
2994 			con_driver->last = MAX_NR_CONSOLES - 1;
2995 			break;
2996 		}
2997 	}
2998 
2999 	for (i = 0; i < MAX_NR_CONSOLES; i++)
3000 		con_driver_map[i] = conswitchp;
3001 
3002 	if (blankinterval) {
3003 		blank_state = blank_normal_wait;
3004 		mod_timer(&console_timer, jiffies + (blankinterval * HZ));
3005 	}
3006 
3007 	for (currcons = 0; currcons < MIN_NR_CONSOLES; currcons++) {
3008 		vc_cons[currcons].d = vc = kzalloc(sizeof(struct vc_data), GFP_NOWAIT);
3009 		INIT_WORK(&vc_cons[currcons].SAK_work, vc_SAK);
3010 		tty_port_init(&vc->port);
3011 		visual_init(vc, currcons, 1);
3012 		vc->vc_screenbuf = kzalloc(vc->vc_screenbuf_size, GFP_NOWAIT);
3013 		vc_init(vc, vc->vc_rows, vc->vc_cols,
3014 			currcons || !vc->vc_sw->con_save_screen);
3015 	}
3016 	currcons = fg_console = 0;
3017 	master_display_fg = vc = vc_cons[currcons].d;
3018 	set_origin(vc);
3019 	save_screen(vc);
3020 	gotoxy(vc, vc->vc_x, vc->vc_y);
3021 	csi_J(vc, 0);
3022 	update_screen(vc);
3023 	pr_info("Console: %s %s %dx%d\n",
3024 		vc->vc_can_do_color ? "colour" : "mono",
3025 		display_desc, vc->vc_cols, vc->vc_rows);
3026 	printable = 1;
3027 
3028 	console_unlock();
3029 
3030 #ifdef CONFIG_VT_CONSOLE
3031 	register_console(&vt_console_driver);
3032 #endif
3033 	return 0;
3034 }
3035 console_initcall(con_init);
3036 
3037 static const struct tty_operations con_ops = {
3038 	.install = con_install,
3039 	.open = con_open,
3040 	.close = con_close,
3041 	.write = con_write,
3042 	.write_room = con_write_room,
3043 	.put_char = con_put_char,
3044 	.flush_chars = con_flush_chars,
3045 	.chars_in_buffer = con_chars_in_buffer,
3046 	.ioctl = vt_ioctl,
3047 #ifdef CONFIG_COMPAT
3048 	.compat_ioctl = vt_compat_ioctl,
3049 #endif
3050 	.stop = con_stop,
3051 	.start = con_start,
3052 	.throttle = con_throttle,
3053 	.unthrottle = con_unthrottle,
3054 	.resize = vt_resize,
3055 	.shutdown = con_shutdown
3056 };
3057 
3058 static struct cdev vc0_cdev;
3059 
3060 static ssize_t show_tty_active(struct device *dev,
3061 				struct device_attribute *attr, char *buf)
3062 {
3063 	return sprintf(buf, "tty%d\n", fg_console + 1);
3064 }
3065 static DEVICE_ATTR(active, S_IRUGO, show_tty_active, NULL);
3066 
3067 static struct attribute *vt_dev_attrs[] = {
3068 	&dev_attr_active.attr,
3069 	NULL
3070 };
3071 
3072 ATTRIBUTE_GROUPS(vt_dev);
3073 
3074 int __init vty_init(const struct file_operations *console_fops)
3075 {
3076 	cdev_init(&vc0_cdev, console_fops);
3077 	if (cdev_add(&vc0_cdev, MKDEV(TTY_MAJOR, 0), 1) ||
3078 	    register_chrdev_region(MKDEV(TTY_MAJOR, 0), 1, "/dev/vc/0") < 0)
3079 		panic("Couldn't register /dev/tty0 driver\n");
3080 	tty0dev = device_create_with_groups(tty_class, NULL,
3081 					    MKDEV(TTY_MAJOR, 0), NULL,
3082 					    vt_dev_groups, "tty0");
3083 	if (IS_ERR(tty0dev))
3084 		tty0dev = NULL;
3085 
3086 	vcs_init();
3087 
3088 	console_driver = alloc_tty_driver(MAX_NR_CONSOLES);
3089 	if (!console_driver)
3090 		panic("Couldn't allocate console driver\n");
3091 
3092 	console_driver->name = "tty";
3093 	console_driver->name_base = 1;
3094 	console_driver->major = TTY_MAJOR;
3095 	console_driver->minor_start = 1;
3096 	console_driver->type = TTY_DRIVER_TYPE_CONSOLE;
3097 	console_driver->init_termios = tty_std_termios;
3098 	if (default_utf8)
3099 		console_driver->init_termios.c_iflag |= IUTF8;
3100 	console_driver->flags = TTY_DRIVER_REAL_RAW | TTY_DRIVER_RESET_TERMIOS;
3101 	tty_set_operations(console_driver, &con_ops);
3102 	if (tty_register_driver(console_driver))
3103 		panic("Couldn't register console driver\n");
3104 	kbd_init();
3105 	console_map_init();
3106 #ifdef CONFIG_MDA_CONSOLE
3107 	mda_console_init();
3108 #endif
3109 	return 0;
3110 }
3111 
3112 #ifndef VT_SINGLE_DRIVER
3113 
3114 static struct class *vtconsole_class;
3115 
3116 static int do_bind_con_driver(const struct consw *csw, int first, int last,
3117 			   int deflt)
3118 {
3119 	struct module *owner = csw->owner;
3120 	const char *desc = NULL;
3121 	struct con_driver *con_driver;
3122 	int i, j = -1, k = -1, retval = -ENODEV;
3123 
3124 	if (!try_module_get(owner))
3125 		return -ENODEV;
3126 
3127 	WARN_CONSOLE_UNLOCKED();
3128 
3129 	/* check if driver is registered */
3130 	for (i = 0; i < MAX_NR_CON_DRIVER; i++) {
3131 		con_driver = &registered_con_driver[i];
3132 
3133 		if (con_driver->con == csw) {
3134 			desc = con_driver->desc;
3135 			retval = 0;
3136 			break;
3137 		}
3138 	}
3139 
3140 	if (retval)
3141 		goto err;
3142 
3143 	if (!(con_driver->flag & CON_DRIVER_FLAG_INIT)) {
3144 		csw->con_startup();
3145 		con_driver->flag |= CON_DRIVER_FLAG_INIT;
3146 	}
3147 
3148 	if (deflt) {
3149 		if (conswitchp)
3150 			module_put(conswitchp->owner);
3151 
3152 		__module_get(owner);
3153 		conswitchp = csw;
3154 	}
3155 
3156 	first = max(first, con_driver->first);
3157 	last = min(last, con_driver->last);
3158 
3159 	for (i = first; i <= last; i++) {
3160 		int old_was_color;
3161 		struct vc_data *vc = vc_cons[i].d;
3162 
3163 		if (con_driver_map[i])
3164 			module_put(con_driver_map[i]->owner);
3165 		__module_get(owner);
3166 		con_driver_map[i] = csw;
3167 
3168 		if (!vc || !vc->vc_sw)
3169 			continue;
3170 
3171 		j = i;
3172 
3173 		if (con_is_visible(vc)) {
3174 			k = i;
3175 			save_screen(vc);
3176 		}
3177 
3178 		old_was_color = vc->vc_can_do_color;
3179 		vc->vc_sw->con_deinit(vc);
3180 		vc->vc_origin = (unsigned long)vc->vc_screenbuf;
3181 		visual_init(vc, i, 0);
3182 		set_origin(vc);
3183 		update_attr(vc);
3184 
3185 		/* If the console changed between mono <-> color, then
3186 		 * the attributes in the screenbuf will be wrong.  The
3187 		 * following resets all attributes to something sane.
3188 		 */
3189 		if (old_was_color != vc->vc_can_do_color)
3190 			clear_buffer_attributes(vc);
3191 	}
3192 
3193 	pr_info("Console: switching ");
3194 	if (!deflt)
3195 		pr_cont("consoles %d-%d ", first + 1, last + 1);
3196 	if (j >= 0) {
3197 		struct vc_data *vc = vc_cons[j].d;
3198 
3199 		pr_cont("to %s %s %dx%d\n",
3200 			vc->vc_can_do_color ? "colour" : "mono",
3201 			desc, vc->vc_cols, vc->vc_rows);
3202 
3203 		if (k >= 0) {
3204 			vc = vc_cons[k].d;
3205 			update_screen(vc);
3206 		}
3207 	} else {
3208 		pr_cont("to %s\n", desc);
3209 	}
3210 
3211 	retval = 0;
3212 err:
3213 	module_put(owner);
3214 	return retval;
3215 };
3216 
3217 
3218 #ifdef CONFIG_VT_HW_CONSOLE_BINDING
3219 /* unlocked version of unbind_con_driver() */
3220 int do_unbind_con_driver(const struct consw *csw, int first, int last, int deflt)
3221 {
3222 	struct module *owner = csw->owner;
3223 	const struct consw *defcsw = NULL;
3224 	struct con_driver *con_driver = NULL, *con_back = NULL;
3225 	int i, retval = -ENODEV;
3226 
3227 	if (!try_module_get(owner))
3228 		return -ENODEV;
3229 
3230 	WARN_CONSOLE_UNLOCKED();
3231 
3232 	/* check if driver is registered and if it is unbindable */
3233 	for (i = 0; i < MAX_NR_CON_DRIVER; i++) {
3234 		con_driver = &registered_con_driver[i];
3235 
3236 		if (con_driver->con == csw &&
3237 		    con_driver->flag & CON_DRIVER_FLAG_MODULE) {
3238 			retval = 0;
3239 			break;
3240 		}
3241 	}
3242 
3243 	if (retval)
3244 		goto err;
3245 
3246 	retval = -ENODEV;
3247 
3248 	/* check if backup driver exists */
3249 	for (i = 0; i < MAX_NR_CON_DRIVER; i++) {
3250 		con_back = &registered_con_driver[i];
3251 
3252 		if (con_back->con && con_back->con != csw) {
3253 			defcsw = con_back->con;
3254 			retval = 0;
3255 			break;
3256 		}
3257 	}
3258 
3259 	if (retval)
3260 		goto err;
3261 
3262 	if (!con_is_bound(csw))
3263 		goto err;
3264 
3265 	first = max(first, con_driver->first);
3266 	last = min(last, con_driver->last);
3267 
3268 	for (i = first; i <= last; i++) {
3269 		if (con_driver_map[i] == csw) {
3270 			module_put(csw->owner);
3271 			con_driver_map[i] = NULL;
3272 		}
3273 	}
3274 
3275 	if (!con_is_bound(defcsw)) {
3276 		const struct consw *defconsw = conswitchp;
3277 
3278 		defcsw->con_startup();
3279 		con_back->flag |= CON_DRIVER_FLAG_INIT;
3280 		/*
3281 		 * vgacon may change the default driver to point
3282 		 * to dummycon, we restore it here...
3283 		 */
3284 		conswitchp = defconsw;
3285 	}
3286 
3287 	if (!con_is_bound(csw))
3288 		con_driver->flag &= ~CON_DRIVER_FLAG_INIT;
3289 
3290 	/* ignore return value, binding should not fail */
3291 	do_bind_con_driver(defcsw, first, last, deflt);
3292 err:
3293 	module_put(owner);
3294 	return retval;
3295 
3296 }
3297 EXPORT_SYMBOL_GPL(do_unbind_con_driver);
3298 
3299 static int vt_bind(struct con_driver *con)
3300 {
3301 	const struct consw *defcsw = NULL, *csw = NULL;
3302 	int i, more = 1, first = -1, last = -1, deflt = 0;
3303 
3304  	if (!con->con || !(con->flag & CON_DRIVER_FLAG_MODULE))
3305 		goto err;
3306 
3307 	csw = con->con;
3308 
3309 	for (i = 0; i < MAX_NR_CON_DRIVER; i++) {
3310 		struct con_driver *con = &registered_con_driver[i];
3311 
3312 		if (con->con && !(con->flag & CON_DRIVER_FLAG_MODULE)) {
3313 			defcsw = con->con;
3314 			break;
3315 		}
3316 	}
3317 
3318 	if (!defcsw)
3319 		goto err;
3320 
3321 	while (more) {
3322 		more = 0;
3323 
3324 		for (i = con->first; i <= con->last; i++) {
3325 			if (con_driver_map[i] == defcsw) {
3326 				if (first == -1)
3327 					first = i;
3328 				last = i;
3329 				more = 1;
3330 			} else if (first != -1)
3331 				break;
3332 		}
3333 
3334 		if (first == 0 && last == MAX_NR_CONSOLES -1)
3335 			deflt = 1;
3336 
3337 		if (first != -1)
3338 			do_bind_con_driver(csw, first, last, deflt);
3339 
3340 		first = -1;
3341 		last = -1;
3342 		deflt = 0;
3343 	}
3344 
3345 err:
3346 	return 0;
3347 }
3348 
3349 static int vt_unbind(struct con_driver *con)
3350 {
3351 	const struct consw *csw = NULL;
3352 	int i, more = 1, first = -1, last = -1, deflt = 0;
3353 	int ret;
3354 
3355  	if (!con->con || !(con->flag & CON_DRIVER_FLAG_MODULE))
3356 		goto err;
3357 
3358 	csw = con->con;
3359 
3360 	while (more) {
3361 		more = 0;
3362 
3363 		for (i = con->first; i <= con->last; i++) {
3364 			if (con_driver_map[i] == csw) {
3365 				if (first == -1)
3366 					first = i;
3367 				last = i;
3368 				more = 1;
3369 			} else if (first != -1)
3370 				break;
3371 		}
3372 
3373 		if (first == 0 && last == MAX_NR_CONSOLES -1)
3374 			deflt = 1;
3375 
3376 		if (first != -1) {
3377 			ret = do_unbind_con_driver(csw, first, last, deflt);
3378 			if (ret != 0)
3379 				return ret;
3380 		}
3381 
3382 		first = -1;
3383 		last = -1;
3384 		deflt = 0;
3385 	}
3386 
3387 err:
3388 	return 0;
3389 }
3390 #else
3391 static inline int vt_bind(struct con_driver *con)
3392 {
3393 	return 0;
3394 }
3395 static inline int vt_unbind(struct con_driver *con)
3396 {
3397 	return 0;
3398 }
3399 #endif /* CONFIG_VT_HW_CONSOLE_BINDING */
3400 
3401 static ssize_t store_bind(struct device *dev, struct device_attribute *attr,
3402 			  const char *buf, size_t count)
3403 {
3404 	struct con_driver *con = dev_get_drvdata(dev);
3405 	int bind = simple_strtoul(buf, NULL, 0);
3406 
3407 	console_lock();
3408 
3409 	if (bind)
3410 		vt_bind(con);
3411 	else
3412 		vt_unbind(con);
3413 
3414 	console_unlock();
3415 
3416 	return count;
3417 }
3418 
3419 static ssize_t show_bind(struct device *dev, struct device_attribute *attr,
3420 			 char *buf)
3421 {
3422 	struct con_driver *con = dev_get_drvdata(dev);
3423 	int bind = con_is_bound(con->con);
3424 
3425 	return snprintf(buf, PAGE_SIZE, "%i\n", bind);
3426 }
3427 
3428 static ssize_t show_name(struct device *dev, struct device_attribute *attr,
3429 			 char *buf)
3430 {
3431 	struct con_driver *con = dev_get_drvdata(dev);
3432 
3433 	return snprintf(buf, PAGE_SIZE, "%s %s\n",
3434 			(con->flag & CON_DRIVER_FLAG_MODULE) ? "(M)" : "(S)",
3435 			 con->desc);
3436 
3437 }
3438 
3439 static DEVICE_ATTR(bind, S_IRUGO|S_IWUSR, show_bind, store_bind);
3440 static DEVICE_ATTR(name, S_IRUGO, show_name, NULL);
3441 
3442 static struct attribute *con_dev_attrs[] = {
3443 	&dev_attr_bind.attr,
3444 	&dev_attr_name.attr,
3445 	NULL
3446 };
3447 
3448 ATTRIBUTE_GROUPS(con_dev);
3449 
3450 static int vtconsole_init_device(struct con_driver *con)
3451 {
3452 	con->flag |= CON_DRIVER_FLAG_ATTR;
3453 	return 0;
3454 }
3455 
3456 static void vtconsole_deinit_device(struct con_driver *con)
3457 {
3458 	con->flag &= ~CON_DRIVER_FLAG_ATTR;
3459 }
3460 
3461 /**
3462  * con_is_bound - checks if driver is bound to the console
3463  * @csw: console driver
3464  *
3465  * RETURNS: zero if unbound, nonzero if bound
3466  *
3467  * Drivers can call this and if zero, they should release
3468  * all resources allocated on con_startup()
3469  */
3470 int con_is_bound(const struct consw *csw)
3471 {
3472 	int i, bound = 0;
3473 
3474 	for (i = 0; i < MAX_NR_CONSOLES; i++) {
3475 		if (con_driver_map[i] == csw) {
3476 			bound = 1;
3477 			break;
3478 		}
3479 	}
3480 
3481 	return bound;
3482 }
3483 EXPORT_SYMBOL(con_is_bound);
3484 
3485 /**
3486  * con_debug_enter - prepare the console for the kernel debugger
3487  * @sw: console driver
3488  *
3489  * Called when the console is taken over by the kernel debugger, this
3490  * function needs to save the current console state, then put the console
3491  * into a state suitable for the kernel debugger.
3492  *
3493  * RETURNS:
3494  * Zero on success, nonzero if a failure occurred when trying to prepare
3495  * the console for the debugger.
3496  */
3497 int con_debug_enter(struct vc_data *vc)
3498 {
3499 	int ret = 0;
3500 
3501 	saved_fg_console = fg_console;
3502 	saved_last_console = last_console;
3503 	saved_want_console = want_console;
3504 	saved_vc_mode = vc->vc_mode;
3505 	saved_console_blanked = console_blanked;
3506 	vc->vc_mode = KD_TEXT;
3507 	console_blanked = 0;
3508 	if (vc->vc_sw->con_debug_enter)
3509 		ret = vc->vc_sw->con_debug_enter(vc);
3510 #ifdef CONFIG_KGDB_KDB
3511 	/* Set the initial LINES variable if it is not already set */
3512 	if (vc->vc_rows < 999) {
3513 		int linecount;
3514 		char lns[4];
3515 		const char *setargs[3] = {
3516 			"set",
3517 			"LINES",
3518 			lns,
3519 		};
3520 		if (kdbgetintenv(setargs[0], &linecount)) {
3521 			snprintf(lns, 4, "%i", vc->vc_rows);
3522 			kdb_set(2, setargs);
3523 		}
3524 	}
3525 	if (vc->vc_cols < 999) {
3526 		int colcount;
3527 		char cols[4];
3528 		const char *setargs[3] = {
3529 			"set",
3530 			"COLUMNS",
3531 			cols,
3532 		};
3533 		if (kdbgetintenv(setargs[0], &colcount)) {
3534 			snprintf(cols, 4, "%i", vc->vc_cols);
3535 			kdb_set(2, setargs);
3536 		}
3537 	}
3538 #endif /* CONFIG_KGDB_KDB */
3539 	return ret;
3540 }
3541 EXPORT_SYMBOL_GPL(con_debug_enter);
3542 
3543 /**
3544  * con_debug_leave - restore console state
3545  * @sw: console driver
3546  *
3547  * Restore the console state to what it was before the kernel debugger
3548  * was invoked.
3549  *
3550  * RETURNS:
3551  * Zero on success, nonzero if a failure occurred when trying to restore
3552  * the console.
3553  */
3554 int con_debug_leave(void)
3555 {
3556 	struct vc_data *vc;
3557 	int ret = 0;
3558 
3559 	fg_console = saved_fg_console;
3560 	last_console = saved_last_console;
3561 	want_console = saved_want_console;
3562 	console_blanked = saved_console_blanked;
3563 	vc_cons[fg_console].d->vc_mode = saved_vc_mode;
3564 
3565 	vc = vc_cons[fg_console].d;
3566 	if (vc->vc_sw->con_debug_leave)
3567 		ret = vc->vc_sw->con_debug_leave(vc);
3568 	return ret;
3569 }
3570 EXPORT_SYMBOL_GPL(con_debug_leave);
3571 
3572 static int do_register_con_driver(const struct consw *csw, int first, int last)
3573 {
3574 	struct module *owner = csw->owner;
3575 	struct con_driver *con_driver;
3576 	const char *desc;
3577 	int i, retval;
3578 
3579 	WARN_CONSOLE_UNLOCKED();
3580 
3581 	if (!try_module_get(owner))
3582 		return -ENODEV;
3583 
3584 	for (i = 0; i < MAX_NR_CON_DRIVER; i++) {
3585 		con_driver = &registered_con_driver[i];
3586 
3587 		/* already registered */
3588 		if (con_driver->con == csw) {
3589 			retval = -EBUSY;
3590 			goto err;
3591 		}
3592 	}
3593 
3594 	desc = csw->con_startup();
3595 	if (!desc) {
3596 		retval = -ENODEV;
3597 		goto err;
3598 	}
3599 
3600 	retval = -EINVAL;
3601 
3602 	for (i = 0; i < MAX_NR_CON_DRIVER; i++) {
3603 		con_driver = &registered_con_driver[i];
3604 
3605 		if (con_driver->con == NULL &&
3606 		    !(con_driver->flag & CON_DRIVER_FLAG_ZOMBIE)) {
3607 			con_driver->con = csw;
3608 			con_driver->desc = desc;
3609 			con_driver->node = i;
3610 			con_driver->flag = CON_DRIVER_FLAG_MODULE |
3611 			                   CON_DRIVER_FLAG_INIT;
3612 			con_driver->first = first;
3613 			con_driver->last = last;
3614 			retval = 0;
3615 			break;
3616 		}
3617 	}
3618 
3619 	if (retval)
3620 		goto err;
3621 
3622 	con_driver->dev =
3623 		device_create_with_groups(vtconsole_class, NULL,
3624 					  MKDEV(0, con_driver->node),
3625 					  con_driver, con_dev_groups,
3626 					  "vtcon%i", con_driver->node);
3627 	if (IS_ERR(con_driver->dev)) {
3628 		pr_warn("Unable to create device for %s; errno = %ld\n",
3629 			con_driver->desc, PTR_ERR(con_driver->dev));
3630 		con_driver->dev = NULL;
3631 	} else {
3632 		vtconsole_init_device(con_driver);
3633 	}
3634 
3635 err:
3636 	module_put(owner);
3637 	return retval;
3638 }
3639 
3640 
3641 /**
3642  * do_unregister_con_driver - unregister console driver from console layer
3643  * @csw: console driver
3644  *
3645  * DESCRIPTION: All drivers that registers to the console layer must
3646  * call this function upon exit, or if the console driver is in a state
3647  * where it won't be able to handle console services, such as the
3648  * framebuffer console without loaded framebuffer drivers.
3649  *
3650  * The driver must unbind first prior to unregistration.
3651  */
3652 int do_unregister_con_driver(const struct consw *csw)
3653 {
3654 	int i;
3655 
3656 	/* cannot unregister a bound driver */
3657 	if (con_is_bound(csw))
3658 		return -EBUSY;
3659 
3660 	if (csw == conswitchp)
3661 		return -EINVAL;
3662 
3663 	for (i = 0; i < MAX_NR_CON_DRIVER; i++) {
3664 		struct con_driver *con_driver = &registered_con_driver[i];
3665 
3666 		if (con_driver->con == csw) {
3667 			/*
3668 			 * Defer the removal of the sysfs entries since that
3669 			 * will acquire the kernfs s_active lock and we can't
3670 			 * acquire this lock while holding the console lock:
3671 			 * the unbind sysfs entry imposes already the opposite
3672 			 * order. Reset con already here to prevent any later
3673 			 * lookup to succeed and mark this slot as zombie, so
3674 			 * it won't get reused until we complete the removal
3675 			 * in the deferred work.
3676 			 */
3677 			con_driver->con = NULL;
3678 			con_driver->flag = CON_DRIVER_FLAG_ZOMBIE;
3679 			schedule_work(&con_driver_unregister_work);
3680 
3681 			return 0;
3682 		}
3683 	}
3684 
3685 	return -ENODEV;
3686 }
3687 EXPORT_SYMBOL_GPL(do_unregister_con_driver);
3688 
3689 static void con_driver_unregister_callback(struct work_struct *ignored)
3690 {
3691 	int i;
3692 
3693 	console_lock();
3694 
3695 	for (i = 0; i < MAX_NR_CON_DRIVER; i++) {
3696 		struct con_driver *con_driver = &registered_con_driver[i];
3697 
3698 		if (!(con_driver->flag & CON_DRIVER_FLAG_ZOMBIE))
3699 			continue;
3700 
3701 		console_unlock();
3702 
3703 		vtconsole_deinit_device(con_driver);
3704 		device_destroy(vtconsole_class, MKDEV(0, con_driver->node));
3705 
3706 		console_lock();
3707 
3708 		if (WARN_ON_ONCE(con_driver->con))
3709 			con_driver->con = NULL;
3710 		con_driver->desc = NULL;
3711 		con_driver->dev = NULL;
3712 		con_driver->node = 0;
3713 		WARN_ON_ONCE(con_driver->flag != CON_DRIVER_FLAG_ZOMBIE);
3714 		con_driver->flag = 0;
3715 		con_driver->first = 0;
3716 		con_driver->last = 0;
3717 	}
3718 
3719 	console_unlock();
3720 }
3721 
3722 /*
3723  *	If we support more console drivers, this function is used
3724  *	when a driver wants to take over some existing consoles
3725  *	and become default driver for newly opened ones.
3726  *
3727  *	do_take_over_console is basically a register followed by unbind
3728  */
3729 int do_take_over_console(const struct consw *csw, int first, int last, int deflt)
3730 {
3731 	int err;
3732 
3733 	err = do_register_con_driver(csw, first, last);
3734 	/*
3735 	 * If we get an busy error we still want to bind the console driver
3736 	 * and return success, as we may have unbound the console driver
3737 	 * but not unregistered it.
3738 	 */
3739 	if (err == -EBUSY)
3740 		err = 0;
3741 	if (!err)
3742 		do_bind_con_driver(csw, first, last, deflt);
3743 
3744 	return err;
3745 }
3746 EXPORT_SYMBOL_GPL(do_take_over_console);
3747 
3748 
3749 /*
3750  * give_up_console is a wrapper to unregister_con_driver. It will only
3751  * work if driver is fully unbound.
3752  */
3753 void give_up_console(const struct consw *csw)
3754 {
3755 	console_lock();
3756 	do_unregister_con_driver(csw);
3757 	console_unlock();
3758 }
3759 
3760 static int __init vtconsole_class_init(void)
3761 {
3762 	int i;
3763 
3764 	vtconsole_class = class_create(THIS_MODULE, "vtconsole");
3765 	if (IS_ERR(vtconsole_class)) {
3766 		pr_warn("Unable to create vt console class; errno = %ld\n",
3767 			PTR_ERR(vtconsole_class));
3768 		vtconsole_class = NULL;
3769 	}
3770 
3771 	/* Add system drivers to sysfs */
3772 	for (i = 0; i < MAX_NR_CON_DRIVER; i++) {
3773 		struct con_driver *con = &registered_con_driver[i];
3774 
3775 		if (con->con && !con->dev) {
3776 			con->dev =
3777 				device_create_with_groups(vtconsole_class, NULL,
3778 							  MKDEV(0, con->node),
3779 							  con, con_dev_groups,
3780 							  "vtcon%i", con->node);
3781 
3782 			if (IS_ERR(con->dev)) {
3783 				pr_warn("Unable to create device for %s; errno = %ld\n",
3784 					con->desc, PTR_ERR(con->dev));
3785 				con->dev = NULL;
3786 			} else {
3787 				vtconsole_init_device(con);
3788 			}
3789 		}
3790 	}
3791 
3792 	return 0;
3793 }
3794 postcore_initcall(vtconsole_class_init);
3795 
3796 #endif
3797 
3798 /*
3799  *	Screen blanking
3800  */
3801 
3802 static int set_vesa_blanking(char __user *p)
3803 {
3804 	unsigned int mode;
3805 
3806 	if (get_user(mode, p + 1))
3807 		return -EFAULT;
3808 
3809 	vesa_blank_mode = (mode < 4) ? mode : 0;
3810 	return 0;
3811 }
3812 
3813 void do_blank_screen(int entering_gfx)
3814 {
3815 	struct vc_data *vc = vc_cons[fg_console].d;
3816 	int i;
3817 
3818 	WARN_CONSOLE_UNLOCKED();
3819 
3820 	if (console_blanked) {
3821 		if (blank_state == blank_vesa_wait) {
3822 			blank_state = blank_off;
3823 			vc->vc_sw->con_blank(vc, vesa_blank_mode + 1, 0);
3824 		}
3825 		return;
3826 	}
3827 
3828 	/* entering graphics mode? */
3829 	if (entering_gfx) {
3830 		hide_cursor(vc);
3831 		save_screen(vc);
3832 		vc->vc_sw->con_blank(vc, -1, 1);
3833 		console_blanked = fg_console + 1;
3834 		blank_state = blank_off;
3835 		set_origin(vc);
3836 		return;
3837 	}
3838 
3839 	if (blank_state != blank_normal_wait)
3840 		return;
3841 	blank_state = blank_off;
3842 
3843 	/* don't blank graphics */
3844 	if (vc->vc_mode != KD_TEXT) {
3845 		console_blanked = fg_console + 1;
3846 		return;
3847 	}
3848 
3849 	hide_cursor(vc);
3850 	del_timer_sync(&console_timer);
3851 	blank_timer_expired = 0;
3852 
3853 	save_screen(vc);
3854 	/* In case we need to reset origin, blanking hook returns 1 */
3855 	i = vc->vc_sw->con_blank(vc, vesa_off_interval ? 1 : (vesa_blank_mode + 1), 0);
3856 	console_blanked = fg_console + 1;
3857 	if (i)
3858 		set_origin(vc);
3859 
3860 	if (console_blank_hook && console_blank_hook(1))
3861 		return;
3862 
3863 	if (vesa_off_interval && vesa_blank_mode) {
3864 		blank_state = blank_vesa_wait;
3865 		mod_timer(&console_timer, jiffies + vesa_off_interval);
3866 	}
3867 	vt_event_post(VT_EVENT_BLANK, vc->vc_num, vc->vc_num);
3868 }
3869 EXPORT_SYMBOL(do_blank_screen);
3870 
3871 /*
3872  * Called by timer as well as from vt_console_driver
3873  */
3874 void do_unblank_screen(int leaving_gfx)
3875 {
3876 	struct vc_data *vc;
3877 
3878 	/* This should now always be called from a "sane" (read: can schedule)
3879 	 * context for the sake of the low level drivers, except in the special
3880 	 * case of oops_in_progress
3881 	 */
3882 	if (!oops_in_progress)
3883 		might_sleep();
3884 
3885 	WARN_CONSOLE_UNLOCKED();
3886 
3887 	ignore_poke = 0;
3888 	if (!console_blanked)
3889 		return;
3890 	if (!vc_cons_allocated(fg_console)) {
3891 		/* impossible */
3892 		pr_warn("unblank_screen: tty %d not allocated ??\n",
3893 			fg_console + 1);
3894 		return;
3895 	}
3896 	vc = vc_cons[fg_console].d;
3897 	/* Try to unblank in oops case too */
3898 	if (vc->vc_mode != KD_TEXT && !vt_force_oops_output(vc))
3899 		return; /* but leave console_blanked != 0 */
3900 
3901 	if (blankinterval) {
3902 		mod_timer(&console_timer, jiffies + (blankinterval * HZ));
3903 		blank_state = blank_normal_wait;
3904 	}
3905 
3906 	console_blanked = 0;
3907 	if (vc->vc_sw->con_blank(vc, 0, leaving_gfx) || vt_force_oops_output(vc))
3908 		/* Low-level driver cannot restore -> do it ourselves */
3909 		update_screen(vc);
3910 	if (console_blank_hook)
3911 		console_blank_hook(0);
3912 	set_palette(vc);
3913 	set_cursor(vc);
3914 	vt_event_post(VT_EVENT_UNBLANK, vc->vc_num, vc->vc_num);
3915 }
3916 EXPORT_SYMBOL(do_unblank_screen);
3917 
3918 /*
3919  * This is called by the outside world to cause a forced unblank, mostly for
3920  * oopses. Currently, I just call do_unblank_screen(0), but we could eventually
3921  * call it with 1 as an argument and so force a mode restore... that may kill
3922  * X or at least garbage the screen but would also make the Oops visible...
3923  */
3924 void unblank_screen(void)
3925 {
3926 	do_unblank_screen(0);
3927 }
3928 
3929 /*
3930  * We defer the timer blanking to work queue so it can take the console mutex
3931  * (console operations can still happen at irq time, but only from printk which
3932  * has the console mutex. Not perfect yet, but better than no locking
3933  */
3934 static void blank_screen_t(struct timer_list *unused)
3935 {
3936 	blank_timer_expired = 1;
3937 	schedule_work(&console_work);
3938 }
3939 
3940 void poke_blanked_console(void)
3941 {
3942 	WARN_CONSOLE_UNLOCKED();
3943 
3944 	/* Add this so we quickly catch whoever might call us in a non
3945 	 * safe context. Nowadays, unblank_screen() isn't to be called in
3946 	 * atomic contexts and is allowed to schedule (with the special case
3947 	 * of oops_in_progress, but that isn't of any concern for this
3948 	 * function. --BenH.
3949 	 */
3950 	might_sleep();
3951 
3952 	/* This isn't perfectly race free, but a race here would be mostly harmless,
3953 	 * at worse, we'll do a spurrious blank and it's unlikely
3954 	 */
3955 	del_timer(&console_timer);
3956 	blank_timer_expired = 0;
3957 
3958 	if (ignore_poke || !vc_cons[fg_console].d || vc_cons[fg_console].d->vc_mode == KD_GRAPHICS)
3959 		return;
3960 	if (console_blanked)
3961 		unblank_screen();
3962 	else if (blankinterval) {
3963 		mod_timer(&console_timer, jiffies + (blankinterval * HZ));
3964 		blank_state = blank_normal_wait;
3965 	}
3966 }
3967 
3968 /*
3969  *	Palettes
3970  */
3971 
3972 static void set_palette(struct vc_data *vc)
3973 {
3974 	WARN_CONSOLE_UNLOCKED();
3975 
3976 	if (vc->vc_mode != KD_GRAPHICS && vc->vc_sw->con_set_palette)
3977 		vc->vc_sw->con_set_palette(vc, color_table);
3978 }
3979 
3980 /*
3981  * Load palette into the DAC registers. arg points to a colour
3982  * map, 3 bytes per colour, 16 colours, range from 0 to 255.
3983  */
3984 
3985 int con_set_cmap(unsigned char __user *arg)
3986 {
3987 	int i, j, k;
3988 	unsigned char colormap[3*16];
3989 
3990 	if (copy_from_user(colormap, arg, sizeof(colormap)))
3991 		return -EFAULT;
3992 
3993 	console_lock();
3994 	for (i = k = 0; i < 16; i++) {
3995 		default_red[i] = colormap[k++];
3996 		default_grn[i] = colormap[k++];
3997 		default_blu[i] = colormap[k++];
3998 	}
3999 	for (i = 0; i < MAX_NR_CONSOLES; i++) {
4000 		if (!vc_cons_allocated(i))
4001 			continue;
4002 		for (j = k = 0; j < 16; j++) {
4003 			vc_cons[i].d->vc_palette[k++] = default_red[j];
4004 			vc_cons[i].d->vc_palette[k++] = default_grn[j];
4005 			vc_cons[i].d->vc_palette[k++] = default_blu[j];
4006 		}
4007 		set_palette(vc_cons[i].d);
4008 	}
4009 	console_unlock();
4010 
4011 	return 0;
4012 }
4013 
4014 int con_get_cmap(unsigned char __user *arg)
4015 {
4016 	int i, k;
4017 	unsigned char colormap[3*16];
4018 
4019 	console_lock();
4020 	for (i = k = 0; i < 16; i++) {
4021 		colormap[k++] = default_red[i];
4022 		colormap[k++] = default_grn[i];
4023 		colormap[k++] = default_blu[i];
4024 	}
4025 	console_unlock();
4026 
4027 	if (copy_to_user(arg, colormap, sizeof(colormap)))
4028 		return -EFAULT;
4029 
4030 	return 0;
4031 }
4032 
4033 void reset_palette(struct vc_data *vc)
4034 {
4035 	int j, k;
4036 	for (j=k=0; j<16; j++) {
4037 		vc->vc_palette[k++] = default_red[j];
4038 		vc->vc_palette[k++] = default_grn[j];
4039 		vc->vc_palette[k++] = default_blu[j];
4040 	}
4041 	set_palette(vc);
4042 }
4043 
4044 /*
4045  *  Font switching
4046  *
4047  *  Currently we only support fonts up to 32 pixels wide, at a maximum height
4048  *  of 32 pixels. Userspace fontdata is stored with 32 bytes (shorts/ints,
4049  *  depending on width) reserved for each character which is kinda wasty, but
4050  *  this is done in order to maintain compatibility with the EGA/VGA fonts. It
4051  *  is up to the actual low-level console-driver convert data into its favorite
4052  *  format (maybe we should add a `fontoffset' field to the `display'
4053  *  structure so we won't have to convert the fontdata all the time.
4054  *  /Jes
4055  */
4056 
4057 #define max_font_size 65536
4058 
4059 static int con_font_get(struct vc_data *vc, struct console_font_op *op)
4060 {
4061 	struct console_font font;
4062 	int rc = -EINVAL;
4063 	int c;
4064 
4065 	if (op->data) {
4066 		font.data = kmalloc(max_font_size, GFP_KERNEL);
4067 		if (!font.data)
4068 			return -ENOMEM;
4069 	} else
4070 		font.data = NULL;
4071 
4072 	console_lock();
4073 	if (vc->vc_mode != KD_TEXT)
4074 		rc = -EINVAL;
4075 	else if (vc->vc_sw->con_font_get)
4076 		rc = vc->vc_sw->con_font_get(vc, &font);
4077 	else
4078 		rc = -ENOSYS;
4079 	console_unlock();
4080 
4081 	if (rc)
4082 		goto out;
4083 
4084 	c = (font.width+7)/8 * 32 * font.charcount;
4085 
4086 	if (op->data && font.charcount > op->charcount)
4087 		rc = -ENOSPC;
4088 	if (!(op->flags & KD_FONT_FLAG_OLD)) {
4089 		if (font.width > op->width || font.height > op->height)
4090 			rc = -ENOSPC;
4091 	} else {
4092 		if (font.width != 8)
4093 			rc = -EIO;
4094 		else if ((op->height && font.height > op->height) ||
4095 			 font.height > 32)
4096 			rc = -ENOSPC;
4097 	}
4098 	if (rc)
4099 		goto out;
4100 
4101 	op->height = font.height;
4102 	op->width = font.width;
4103 	op->charcount = font.charcount;
4104 
4105 	if (op->data && copy_to_user(op->data, font.data, c))
4106 		rc = -EFAULT;
4107 
4108 out:
4109 	kfree(font.data);
4110 	return rc;
4111 }
4112 
4113 static int con_font_set(struct vc_data *vc, struct console_font_op *op)
4114 {
4115 	struct console_font font;
4116 	int rc = -EINVAL;
4117 	int size;
4118 
4119 	if (vc->vc_mode != KD_TEXT)
4120 		return -EINVAL;
4121 	if (!op->data)
4122 		return -EINVAL;
4123 	if (op->charcount > 512)
4124 		return -EINVAL;
4125 	if (op->width <= 0 || op->width > 32 || op->height > 32)
4126 		return -EINVAL;
4127 	size = (op->width+7)/8 * 32 * op->charcount;
4128 	if (size > max_font_size)
4129 		return -ENOSPC;
4130 
4131 	font.data = memdup_user(op->data, size);
4132 	if (IS_ERR(font.data))
4133 		return PTR_ERR(font.data);
4134 
4135 	if (!op->height) {		/* Need to guess font height [compat] */
4136 		int h, i;
4137 		u8 *charmap = font.data;
4138 
4139 		/*
4140 		 * If from KDFONTOP ioctl, don't allow things which can be done
4141 		 * in userland,so that we can get rid of this soon
4142 		 */
4143 		if (!(op->flags & KD_FONT_FLAG_OLD)) {
4144 			kfree(font.data);
4145 			return -EINVAL;
4146 		}
4147 
4148 		for (h = 32; h > 0; h--)
4149 			for (i = 0; i < op->charcount; i++)
4150 				if (charmap[32*i+h-1])
4151 					goto nonzero;
4152 
4153 		kfree(font.data);
4154 		return -EINVAL;
4155 
4156 	nonzero:
4157 		op->height = h;
4158 	}
4159 
4160 	font.charcount = op->charcount;
4161 	font.width = op->width;
4162 	font.height = op->height;
4163 
4164 	console_lock();
4165 	if (vc->vc_mode != KD_TEXT)
4166 		rc = -EINVAL;
4167 	else if (vc->vc_sw->con_font_set)
4168 		rc = vc->vc_sw->con_font_set(vc, &font, op->flags);
4169 	else
4170 		rc = -ENOSYS;
4171 	console_unlock();
4172 	kfree(font.data);
4173 	return rc;
4174 }
4175 
4176 static int con_font_default(struct vc_data *vc, struct console_font_op *op)
4177 {
4178 	struct console_font font = {.width = op->width, .height = op->height};
4179 	char name[MAX_FONT_NAME];
4180 	char *s = name;
4181 	int rc;
4182 
4183 
4184 	if (!op->data)
4185 		s = NULL;
4186 	else if (strncpy_from_user(name, op->data, MAX_FONT_NAME - 1) < 0)
4187 		return -EFAULT;
4188 	else
4189 		name[MAX_FONT_NAME - 1] = 0;
4190 
4191 	console_lock();
4192 	if (vc->vc_mode != KD_TEXT) {
4193 		console_unlock();
4194 		return -EINVAL;
4195 	}
4196 	if (vc->vc_sw->con_font_default)
4197 		rc = vc->vc_sw->con_font_default(vc, &font, s);
4198 	else
4199 		rc = -ENOSYS;
4200 	console_unlock();
4201 	if (!rc) {
4202 		op->width = font.width;
4203 		op->height = font.height;
4204 	}
4205 	return rc;
4206 }
4207 
4208 static int con_font_copy(struct vc_data *vc, struct console_font_op *op)
4209 {
4210 	int con = op->height;
4211 	int rc;
4212 
4213 
4214 	console_lock();
4215 	if (vc->vc_mode != KD_TEXT)
4216 		rc = -EINVAL;
4217 	else if (!vc->vc_sw->con_font_copy)
4218 		rc = -ENOSYS;
4219 	else if (con < 0 || !vc_cons_allocated(con))
4220 		rc = -ENOTTY;
4221 	else if (con == vc->vc_num)	/* nothing to do */
4222 		rc = 0;
4223 	else
4224 		rc = vc->vc_sw->con_font_copy(vc, con);
4225 	console_unlock();
4226 	return rc;
4227 }
4228 
4229 int con_font_op(struct vc_data *vc, struct console_font_op *op)
4230 {
4231 	switch (op->op) {
4232 	case KD_FONT_OP_SET:
4233 		return con_font_set(vc, op);
4234 	case KD_FONT_OP_GET:
4235 		return con_font_get(vc, op);
4236 	case KD_FONT_OP_SET_DEFAULT:
4237 		return con_font_default(vc, op);
4238 	case KD_FONT_OP_COPY:
4239 		return con_font_copy(vc, op);
4240 	}
4241 	return -ENOSYS;
4242 }
4243 
4244 /*
4245  *	Interface exported to selection and vcs.
4246  */
4247 
4248 /* used by selection */
4249 u16 screen_glyph(struct vc_data *vc, int offset)
4250 {
4251 	u16 w = scr_readw(screenpos(vc, offset, 1));
4252 	u16 c = w & 0xff;
4253 
4254 	if (w & vc->vc_hi_font_mask)
4255 		c |= 0x100;
4256 	return c;
4257 }
4258 EXPORT_SYMBOL_GPL(screen_glyph);
4259 
4260 /* used by vcs - note the word offset */
4261 unsigned short *screen_pos(struct vc_data *vc, int w_offset, int viewed)
4262 {
4263 	return screenpos(vc, 2 * w_offset, viewed);
4264 }
4265 EXPORT_SYMBOL_GPL(screen_pos);
4266 
4267 void getconsxy(struct vc_data *vc, unsigned char *p)
4268 {
4269 	p[0] = vc->vc_x;
4270 	p[1] = vc->vc_y;
4271 }
4272 
4273 void putconsxy(struct vc_data *vc, unsigned char *p)
4274 {
4275 	hide_cursor(vc);
4276 	gotoxy(vc, p[0], p[1]);
4277 	set_cursor(vc);
4278 }
4279 
4280 u16 vcs_scr_readw(struct vc_data *vc, const u16 *org)
4281 {
4282 	if ((unsigned long)org == vc->vc_pos && softcursor_original != -1)
4283 		return softcursor_original;
4284 	return scr_readw(org);
4285 }
4286 
4287 void vcs_scr_writew(struct vc_data *vc, u16 val, u16 *org)
4288 {
4289 	scr_writew(val, org);
4290 	if ((unsigned long)org == vc->vc_pos) {
4291 		softcursor_original = -1;
4292 		add_softcursor(vc);
4293 	}
4294 }
4295 
4296 void vcs_scr_updated(struct vc_data *vc)
4297 {
4298 	notify_update(vc);
4299 }
4300 
4301 void vc_scrolldelta_helper(struct vc_data *c, int lines,
4302 		unsigned int rolled_over, void *base, unsigned int size)
4303 {
4304 	unsigned long ubase = (unsigned long)base;
4305 	ptrdiff_t scr_end = (void *)c->vc_scr_end - base;
4306 	ptrdiff_t vorigin = (void *)c->vc_visible_origin - base;
4307 	ptrdiff_t origin = (void *)c->vc_origin - base;
4308 	int margin = c->vc_size_row * 4;
4309 	int from, wrap, from_off, avail;
4310 
4311 	/* Turn scrollback off */
4312 	if (!lines) {
4313 		c->vc_visible_origin = c->vc_origin;
4314 		return;
4315 	}
4316 
4317 	/* Do we have already enough to allow jumping from 0 to the end? */
4318 	if (rolled_over > scr_end + margin) {
4319 		from = scr_end;
4320 		wrap = rolled_over + c->vc_size_row;
4321 	} else {
4322 		from = 0;
4323 		wrap = size;
4324 	}
4325 
4326 	from_off = (vorigin - from + wrap) % wrap + lines * c->vc_size_row;
4327 	avail = (origin - from + wrap) % wrap;
4328 
4329 	/* Only a little piece would be left? Show all incl. the piece! */
4330 	if (avail < 2 * margin)
4331 		margin = 0;
4332 	if (from_off < margin)
4333 		from_off = 0;
4334 	if (from_off > avail - margin)
4335 		from_off = avail;
4336 
4337 	c->vc_visible_origin = ubase + (from + from_off) % wrap;
4338 }
4339 EXPORT_SYMBOL_GPL(vc_scrolldelta_helper);
4340 
4341 /*
4342  *	Visible symbols for modules
4343  */
4344 
4345 EXPORT_SYMBOL(color_table);
4346 EXPORT_SYMBOL(default_red);
4347 EXPORT_SYMBOL(default_grn);
4348 EXPORT_SYMBOL(default_blu);
4349 EXPORT_SYMBOL(update_region);
4350 EXPORT_SYMBOL(redraw_screen);
4351 EXPORT_SYMBOL(vc_resize);
4352 EXPORT_SYMBOL(fg_console);
4353 EXPORT_SYMBOL(console_blank_hook);
4354 EXPORT_SYMBOL(console_blanked);
4355 EXPORT_SYMBOL(vc_cons);
4356 EXPORT_SYMBOL(global_cursor_default);
4357 #ifndef VT_SINGLE_DRIVER
4358 EXPORT_SYMBOL(give_up_console);
4359 #endif
4360